Pipe section having polyarylene sulfide composition barrier layer

ABSTRACT

Pipe sections and methods for forming pipe sections are disclosed. A pipe section includes a hollow body, the hollow body having an inner surface and an outer surface, the inner surface defining an interior. The pipe section further includes a barrier layer surrounding the hollow body, the barrier layer having an inner surface and an outer surface. The barrier layer is formed from a polyarylene sulfide composition. The polyarylene sulfide composition includes a polyarylene sulfide and a crosslinked impact modifier. Such pipe sections exhibit high strength characteristics and flexibility as well as resistance to degradation, even in extreme temperature environments, while maintaining desirable processing characteristics.

CROSS REFERENCE TO RELATED APPLICATIONS

The present application claims filing benefit of U.S. Provisional Patentapplication 61/623,618 having a filing date of Apr. 13, 2012; U.S.Provisional Patent application 61/665,423 having a filing date of Jun.28, 2012; U.S. Provisional Patent application 61/678,370 having a filingdate of Aug. 1, 2012; U.S. Provisional Patent application 61/703,331having a filing date of Sep. 20, 2012; U.S. Provisional Patentapplication 61/707,314 having a filing date of Sep. 28, 2012; U.S.Provisional Patent application 61/717,899 having a filing date of Oct.24, 2012; and U.S. Provisional Patent application 61/739,926 having afiling date of Dec. 20, 2012, all of which are incorporated herein byreference in their entirety.

BACKGROUND OF THE INVENTION

Multi-layer pipe assemblies are commonly utilized to convey oil, gas,and/or other suitable fluids. In particular, such pipe assemblies areemployed in the oil and gas industry, such as in subsea applications aswell as in oil and gas production fields. In on-shore or subseaapplications, for, example, multi-layer pipes may be utilized in risers,transfer lines, umbilicals and/or other suitable pipe assemblies. Inproduction field applications, multi-layer pipes may be utilized inrisers, infield flow lines, export pipelines and/or other suitable pipeassemblies.

Multi-layer pipe assemblies, and the pipe sections thereof, typicallyinclude at least two layers; a hollow body or inner layer, and a barrierlayer or outer layer generally surrounding the hollow body. Other layersmay further be included generally surrounding the barrier layer. Variousmaterials have been utilized to form each of these layers in an effortto improve various performance characteristics of the resulting pipesections. Additionally, these layers have been bonded together or leftunbonded, depending on the application and the desired performance ofthe pipe section. For example, U.S. Pat. No. 5,876,648 discloses a pipesection having a metal inner layer and an outer layer formed byparticular shrinkable polymers. U.S. Pat. No. 6,039,083 discloses a pipesection having a metal inner layer and an outer layer formed byparticular polymers. U.S. Pat. No. 8,210,212 discloses a pipe sectionhaving a metal inner layer and a polymer outer layer. U.S. Pat. No.8,163,364 discloses a pipe section having a polymer layer and a filmlayer. U.S. Patent Application No. 2009/0301594 discloses a pipe sectionhaving a metal inner layer and an outer layer formed from apolyphenylene sulfide (PPS). U.S. Patent Application No. 2010/0326558discloses a pipe section having an inner layer and a polymer outerlayer. U.S. Patent Application No. 2011/0041947 discloses a pipe sectionhaving a thermoplastic inner layer and a tape outer layer bonded to theinner layer. Japanese Patent No. 3021435 discloses a pipe section havinga thermoplastic inner layer and a tape outer layer.

The materials utilized in such known pipe assemblies do not provide thecharacteristics required for many applications. For example, in manycases, pipe assemblies are undesirably heavy. Lightweight pipeassemblies formed using polymer materials such as those described above,however, may not exhibit both the flexibility and high strength andresistance properties required by, for example, oil and gasapplications.

Polymer blends that exhibit flexibility in addition to high strength andresistance properties are of significant commercial interest. Suchblends have been formed in the past by uniformly mixing an elasticcomponent with a thermoplastic polyolefin such that the elastomer isintimately and uniformly dispersed as a discrete or co-continuous phasewithin a continuous phase of the polyolefin. Vulcanization of thecomposite crosslinks the components and provides improved temperatureand chemical resistance to the composition. When vulcanization iscarried out during combination of the various polymeric components it istermed dynamic vulcanization.

Polyarylene sulfides are high-performance polymers that may withstandhigh thermal, chemical, and mechanical stresses and are beneficiallyutilized in a wide variety of applications. Polyarylene sulfides haveoften been blended with other polymers to improve characteristics of theproduct composition. For example, elastomeric impact modifiers have beenfound beneficial for improvement of the physical properties of apolyarylene sulfide composition. Compositions including blends ofpolyarylene sulfides with impact modifying polymers have been consideredfor high performance, high temperature applications.

Unfortunately, elastomeric polymers generally considered useful forimpact modification are not compatible with polyarylene sulfides andphase separation has been a problem in forming compositions of the two.Attempts have been made to improve the composition formation, forinstance through the utilization of compatibilizers. However, even uponsuch modifications, compositions including polyarylene sulfides incombination with impact modifying polymers still fail to provide productperformance as desired, particularly in applications that require bothhigh heat and/or chemical resistance and high impact resistance.

Accordingly, improved pipe sections and assemblies formed from such pipesections are desired in the art. In particular, pipe sections thatutilize polyarylene sulfide compositions that exhibit high strengthcharacteristics and flexibility as well as resistance to degradation,even in extreme temperature environments, while maintaining desirableprocessing characteristics, would be advantageous.

SUMMARY OF THE INVENTION

In accordance with one embodiment of the present invention, a pipesection is disclosed. The pipe section includes a hollow body, thehollow body having an inner surface and an outer surface, the innersurface defining an interior. The pipe section further includes abarrier layer surrounding the hollow body, the barrier layer having aninner surface and an outer surface. The barrier layer is formed from atape including a polyarylene sulfide composition, the polyarylenesulfide composition comprising a polyarylene sulfide and a crosslinkedimpact modifier.

In accordance with another embodiment of the present invention, a pipesection is disclosed. The pipe section includes a hollow body, thehollow body having an inner surface and an outer surface, the innersurface defining an interior. The pipe section further includes abarrier layer surrounding the hollow body, the barrier layer having aninner surface and an outer surface. The barrier layer includes acontinuous fiber reinforced polyarylene sulfide composition, thepolyarylene sulfide composition comprising a polyarylene sulfide and acrosslinked impact modifier.

In accordance with another embodiment of the present invention, a methodfor forming a pipe section is disclosed. The method includes surroundinga hollow body with a barrier layer such that the barrier layer is incontact with an outer surface of the hollow body. The barrier layer isformed from a tape comprising a polyarylene sulfide composition, thepolyarylene sulfide composition including a polyarylene sulfide and acrosslinked impact modifier.

Other features and aspects of the present invention are set forth ingreater detail below.

BRIEF DESCRIPTION OF THE DRAWINGS

A full and enabling disclosure of the present invention, including thebest mode thereof to one skilled in the art, is set forth moreparticularly in the remainder of the specification, including referenceto the accompanying figures, in which:

FIG. 1 illustrates various pipe assemblies in a subsea application inaccordance with one embodiment of the present disclosure;

FIG. 2 illustrates various pipe assemblies in a production fieldapplication in accordance with one embodiment of the present disclosure;

FIG. 3 is a perspective view of a multi-layer pipe section having ametal hollow core and unbonded barrier layer in accordance with oneembodiment of the present disclosure;

FIG. 4 is a perspective view of multi-layer pipe section having apolymer hollow core and unbonded barrier layer in accordance withanother embodiment of the present disclosure;

FIG. 5 is a cross-sectional view of a multi-layer pipe section having apolymer hollow core bonded to a barrier layer in accordance with oneembodiment of the present disclosure;

FIG. 6 is a cross-sectional view of a multi-layer pipe section having ametal hollow core bonded to a barrier layer in accordance with anotherembodiment of the present disclosure;

FIG. 7 is a schematic representation of a process for forming apolyarylene sulfide composition in accordance with one embodiment of thepresent disclosure;

FIG. 8 is a schematic illustration of an impregnation system inaccordance with one embodiment of the present disclosure;

FIG. 9 is a perspective view of a die in accordance with one embodimentof the present disclosure;

FIG. 10 is a cross-sectional view of the die shown in FIG. 9;

FIG. 11 is an exploded view of a manifold assembly and gate passage fora die in accordance with one embodiment of the present disclosure;

FIG. 12 is a perspective view of one embodiment of a second impregnationplate at least partially defining an impregnation zone in accordancewith one embodiment of the present disclosure;

FIG. 13 is a close-up cross-sectional view of a portion of animpregnation zone in accordance with one embodiment of the presentdisclosure;

FIG. 14 is a close-up cross-sectional view of a downstream end portionof an impregnation zone in accordance with one embodiment of the presentdisclosure;

FIG. 15 is a perspective view of a land zone in accordance with oneembodiment of the present disclosure;

FIG. 16 is a perspective view of a land zone in accordance with oneembodiment of the present disclosure;

FIG. 17 is a perspective view of a tape in accordance with oneembodiment of the present disclosure;

FIG. 18 is a cross-sectional view a tape in accordance with oneembodiment of the present disclosure;

FIG. 19 illustrates the sample used in determination of melt strengthand melt elongation of polyarylene sulfide compositions describedherein.

FIG. 20 illustrates the effect of temperature change on the notchedCharpy impact strength of a polyarylene sulfide composition as describedherein and that of a comparison composition.

FIG. 21 is a scanning electron microscope image of a polyarylene sulfidecomposition as described herein (FIG. 21A) and a comparison polyarylenesulfide (FIG. 21B).

FIG. 22 compares the effect of sulfuric acid exposure on strengthcharacteristics of polyarylene sulfide compositions as described hereinand a comparison composition.

FIG. 23 provides the log of the complex viscosity obtained forpolyarylene sulfide compositions described herein as a function of theshear rate.

FIG. 24 provides the melt strength of polyarylene sulfide compositionsdescribed herein as a function of the Hencky strain.

FIG. 25 provides the melt elongation for polyarylene sulfidecompositions described herein as a function of Hencky strain.

FIG. 26 illustrates the daily weight loss for testing samples indetermination of permeation resistance of polyarylene sulfidecompositions to CE10 fuel blend.

FIG. 27 illustrates the daily weight loss for testing samples indetermination of permeation resistance of polyarylene sulfidecompositions to CM15A fuel blend.

FIG. 28 illustrates the daily weight loss for testing samples indetermination of permeation resistance of polyarylene sulfidecompositions to methanol.

Repeat use of reference characters in the present specification anddrawings is intended to represent the same or analogous features orelements of the present invention.

DETAILED DESCRIPTION OF REPRESENTATIVE EMBODIMENTS

It is to be understood by one of ordinary skill in the art that thepresent discussion is a description of exemplary embodiments only, andis not intended as limiting the broader aspects of the presentinvention.

Generally speaking, the present disclosure is directed to pipe sectionsand methods for forming pipe sections. The resulting pipe sections maybe utilized in a variety of applications and, in particular, in harshenvironments, such as in oil and gas applications. Advantageously, thematerials utilized to form pipe sections according to the presentdisclosure can be tailored for specific applications so as to withstandspecific environments and the associated temperatures, pHs, abrasion,etc. Pipe sections formed according to the present disclosure areadvantageously lightweight and exhibit flexibility in addition to highstrength and resistance properties.

As discussed in detail below, one or more layers of a multi-layer pipesection formed according to the present disclosure may be formed from apolyarylene sulfide composition that exhibits excellent strength andflexibility characteristics as well as resistance to chemicaldegradation due to contact with, e.g., water, oils, gas, synthetic ornatural chemicals, etc. Beneficially, the polyarylene sulfidecomposition can maintain good physical characteristics even whenutilized in extreme temperature applications such as high temperaturesand low temperatures as may be encountered in piping applications. Thepolyarylene sulfide can also maintain good physical characteristicsunder conditions in which the materials are subjected to extremetemperature fluctuations.

In some embodiments, a pipe section formed according to the presentdisclosure may be utilized in an oil and gas application. For example,in subsea applications, a pipe section formed according to the presentdisclosure may be utilized in a riser, transfer line, umbilical or othersuitable subsea pipe assembly. Risers, transfer lines, etc. may flow oilor gas therethrough. Umbilicals may include various elements fortransferring fluids and/or electric current/signals. For example, anumbilical may contain elongated umbilical elements (e.g., two or more),such as a channel element, fluid pipe, electric conductor/wire (e.g.,optic fiber cable), armoring wire, etc. The pipe section may enclosethese elements. In production field applications, pipe sections formedaccording to the present disclosure may be utilized in risers, infieldflow lines, export pipelines and/or other suitable pipe assemblies.

A pipe section according to the present disclosure includes a hollowbody and one or more barrier layers surrounding the hollow body. Thebarrier layers may be bonded to the hollow body or may be unbounded. Abarrier layer according to the present disclosure is formed from apolyarylene sulfide composition as discussed herein. The polyarylenesulfide composition further may include a plurality of fibers embeddedtherein. Advantageously, continuous fibers may be utilized in thebarrier layer in one embodiment. Further, in exemplary embodiments, thebarrier layer is a tape that includes the polyarylene sulfidecomposition, which may be fiber reinforced. The use of barrier layersformed from a fiber reinforced polyarylene sulfide composition mayimpart numerous advantages to the pipe sections formed therefrom. Theuse of a polyarylene sulfide composition as discussed herein allows suchbarrier layers to be lightweight and exhibit flexibility in addition tohigh strength and resistance properties. Additionally, the use ofcontinuous fibers embedded in the polyarylene sulfide composition canincrease the strength of the barrier layer. The increased strengthprovides, for example, improved burst pressure resistance and tensilestrength. Such fiber reinforced polyarylene sulfide compositions canthus provide the pipe sections with increased strength while allowingthe pipe section to maintain suitable flexibility, etc.

FIG. 1 illustrates one embodiment of a subsea pipe system 10, which isone application in which pipe sections formed according to the presentdisclosure may be utilized. The pipe system 10 may include one or morepipe sections 100, and extends between a subsea facility 14, such as awell bore, and a vessel 16, such as a drilling rig, ship, etc., orbetween two vessels 16, or otherwise. The subsea facility 14 may beadjacent to the bottom 20 of a body of water 22. The vessel 16 and/orsubsea facility 14 may be permanently installed or movable within thebody of water 22. In certain embodiments, the subsea pipe system 10 maybe employed in water having a depth of about 2,500 meters or more, insome embodiments about 4,000 meters or more, and in some embodiments,from about 5,000 to about 15,000 meters. The subsea pipe system 900 mayspan significant portions of these depths.

In exemplary embodiments, a subsea pipe system 10 is utilized totransport a liquid, such as oil, or a gas or other components such aselectrical or other control lines between the subsea facility 14 and thevessel 16, or to contain various elements therein. The pipe system 10may thus include, for example, a riser 24, a transport line 26, anumbilical, or any other suitable pipe for such applications. A pipesection 100 according to the present disclosure may be utilized to formany one or more of these pipe assemblies.

FIG. 2 illustrates a typical production field that can incorporate apipe section according to the present disclosure in various pipeassemblies. As can be seen, the field can include fixed risers 31 thatcan carry production fluid from the sea floor 32 to a platform 35. Thefield can include infield flowlines 33 that can carry production fluid,supporting fluids, umbilicals, etc., within the field. In addition, boththe risers 31 and the infield flowlines 33 can be bundled lines. Thesystem also includes a plurality of tie-ins 34 at which point differentflowlines can be merged, for instance to form a bundled riser and/orwhere individual flowlines may be altered, for instance throughexpansion. The system also includes a plurality of satellite wells 38from which the hydrocarbon production fluid is obtained as well asvarious manifolds. An export pipeline 37 can carry production fluid fromthe platform 35 to shore, a storage facility, or a transport vessel. Theexport pipeline 37 may also include one or more crossings 36 to by-passother flowlines, e.g., another pipeline 39. A pipe section 100 accordingto the present disclosure may be utilized to form any one or more ofthese pipe assemblies

FIGS. 3 through 6 illustrate pipe sections 100 according to variousembodiments of the present disclosure. A pipe section 100 includes ahollow body 102. The hollow body 102 has an inner surface 104 and anouter surface 106, as shown. The inner surface 104 defines an interior108 of the hollow body 102, through which a suitable material, such as aliquid or gas as discussed above, may flow. The hollow body 102 may inexemplary embodiments be generally cylindrical, having a circular oroval-shaped cross-sectional profile. Alternatively, the hollow body 102may have any suitable shape, which may be constant or may vary. Thehollow body 102 may extend along a longitudinal axis 110. It should benoted that the longitudinal direction 110 is a direction generallythrough the center of the hollow body 102, and may correspond forexample to a flow direction through the hollow body 102. Thus, thelongitudinal direction 110 may curve at any suitable angle as requiredbased on the curvature of the hollow body 102.

The hollow body 102 may be formed from any suitable material, which maybe chosen based on the application and environment to which the pipesection 100 is to be exposed. In some embodiments, for example, thehollow body 102 may be formed from a polyarylene sulfide composition. Inother embodiments, the hollow body 102 may be formed from other suitablepolymer materials, which in exemplary embodiments may be thermoplasticmaterials. For example, other suitable thermoplastic polymers for use inthe hollow body 102 may include, for instance, polyolefins (e.g.,polypropylene, propylene-ethylene copolymers, etc.), polyesters (e.g.,polybutylene terephalate (“PBT”)), polycarbonates, polyamides (e.g.,PA12, Nylon™) polyether ketones (e.g., polyether ether ketone (“PEEK”)),polyetherimides, polyarylene ketones (e.g., polyphenylene diketone(“PPDK”)), liquid crystal polymers, polyarylene sulfides (e.g.,polyphenylene sulfide (“PPS”), poly(biphenylene sulfide ketone),poly(phenylene sulfide diketone), poly(biphenylene sulfide), etc.),fluoropolymers (e.g., polytetrafluoroethylene-perfluoromethylvinyletherpolymer, perfluoro-alkoxyalkane polymer, petrafluoroethylene polymer,ethylene-tetrafluoroethylene polymer, etc.), polyacetals, polyurethanes,polycarbonates, styrenic polymers (e.g., acrylonitrile butadiene styrene(“ABS”)), and so forth. FIGS. 4 and 5 illustrate a hollow body formedfrom a polymer material. The polymer material may be extruded to formthe hollow body 102, or otherwise manipulated into the shape of thehollow body 102 as desired or required. In still other embodiments, asshown in FIGS. 3 and 6, the hollow body 102 may be formed from a metal,including metal alloys and superalloys. Steels, such as stainless steeland carbon-based steel, and aluminums are examples of suitable metalsfor use in a hollow body 102. The metal material formed into a hollowbody 102 may be a metal sheet, or may comprise interlocking strips orwires as shown in FIG. 6, which may provide the metal hollow body 102with increased flexibility, or may have any other suitableconfiguration. In some embodiments, the interlocking strips or wires canhave, for example, an S- or Z-cross-sectional configuration, such thatadjacent windings interlock with one another to form a stronger layer.

Hollow bodies 102 formed from polymer materials according to the presentdisclosure may be reinforced or unreinforced. A reinforced hollow body102 may include a plurality of fibers dispersed in the polymer materialforming the hollow body 920. The fibers may be long fibers or continuousfibers. As used therein, the term “long fibers” generally refers tofibers, filaments, yarns, or rovings that are not continuous, and asopposed to “continuous fibers” which generally refer to fibers,filaments, yarns, or rovings having a length that is generally limitedonly by the length of a part. The fibers dispersed in the polymermaterial to form the hollow body 920 may be formed from any conventionalmaterial known in the art, such as metal fibers, glass fibers (e.g.,E-glass, A-glass, C-glass, D-glass, AR-glass, R-glass, S-glass such asS1-glass or S2-glass), carbon fibers (e.g., graphite), boron fibers,ceramic fibers (e.g., alumina or silica), aramid fibers (e.g., Kevlar®marketed by E. I. duPont de Nemours, Wilmington, Del.), syntheticorganic fibers (e.g., polyamide, polyethylene, paraphenylene,terephthalamide, polyethylene terephthalate and polyphenylene sulfide),and various other natural or synthetic inorganic or organic fibrousmaterials known for reinforcing polymer compositions. Glass fibers andcarbon fibers are particularly desirable.

A pipe section 102 according to the present disclosure further includesone or more barrier layers 120. Each barrier layer 120 may generallysurround the hollow body 102. The innermost barrier layer 120 (relativeto the hollow body 102) may be in contact with the hollow body 102, andsurrounding outer barrier layers 120 may each be in contact with theneighboring barrier layer 120, as shown for example in FIG. 4. A barrierlayer 120 has an inner surface 122 and an outer surface 124. When theinnermost barrier layer 120 surrounds the hollow body 102, the innersurface 122 may contact the hollow body 102, such as the outer surface106 thereof.

In some embodiments, multiple barrier layers 120 may bonded to eachother and/or to the hollow body 102, as shown in FIGS. 5 and 6, while inother embodiments, the barrier layers 120 and hollow body 102 may beunbonded, as shown in FIGS. 3 and 4. Bonding of the barrier layers 120and hollow body 102 may involve heating the barrier layers 120 and thehollow body 102, to consolidation temperatures. Heating may be performedin a die, heater, or otherwise during formation of a barrier layer 120or tape thereof, or may be separately performed. A suitable heatingsource may be, for example, infrared, hot gas, laser, or otherwise. Aconsolidation temperature is a temperature that allows the neighboringbarrier layers 120 and/or hollow body 102 to consolidate and thus bebonded together. For example, the consolidation temperature for aparticular polymer resin may be the melting point temperature, or atemperature between approximately 20° C., 15° C., 10° C., or 5° C. belowthe melting point temperature and the melting point temperature for thatpolymer resin. Bonding may further include consolidating the hollow body102 and the barrier layer 120 or the barrier layers 120 together.Consolidation may involve, for example, pressing the hollow body 102 andbarrier layers 120 together, or simply allowing the hollow body 102 andbarrier layers 120 to remain in contact, after heating thereof. Bondingmay further include cooling the resulting pipe section 100 afterconsolidation, and thus bonding, of the hollow body 102 and barrierlayer 120.

As discussed above and in detail below, a barrier layer 120 according tothe present disclosure is formed from a polyarylene sulfide compositionas discussed herein. The polyarylene sulfide composition further mayinclude a plurality of fibers or other fillers embedded therein. Anysuitable fibers as discussed above with respect to the hollow body 102may be utilized in a fiber reinforced polyarylene sulfide composition.Further, in one embodiment, continuous fibers may be utilized in in thebarrier layer 120. In exemplary embodiments, the continuous fibers maybe generally unidirectional. Further, in exemplary embodiments, thebarrier layer 120 is formed from a tape that includes the polyarylenesulfide composition, which may be fiber reinforced. In otherembodiments, the barrier layer 120 may, for example, be extruded overthe hollow body 102.

The polyarylene sulfide composition can be formed according to a meltprocessing technique that includes combining a polyarylene sulfide withan impact modifier to form a mixture and subjecting the mixture todynamic vulcanization. More specifically, the polyarylene sulfide can becombined with the impact modifier and this mixture can be subjected toshear conditions such that the impact modifier becomes well distributedthroughout the polyarylene sulfide. Following formation of the mixture,a polyfunctional crosslinking agent can be added. The polyfunctionalcrosslinking agent can react with the components of the mixture to formcrosslinks in the composition, for instance within and between thepolymer chains of the impact modifier.

Without being bound to any particular theory, it is believed that byadding the polyfunctional crosslinking agent to the polyarylene sulfidecomposition following distribution of the impact modifier throughout thepolyarylene sulfide, interaction between the polyarylene sulfide, theimpact modifier, and the crosslinking agent within the melt processingunit can be improved, leading to improved distribution of thecrosslinked impact modifier throughout the composition. The improveddistribution of the crosslinked impact modifier throughout thecomposition can improve the strength and flexibility characteristics ofthe composition, e.g., the ability of the composition to maintainstrength under deformation, as well as provide a composition with goodprocessibility that can be utilized to form a product that can exhibitexcellent resistance to degradation under a variety of conditions.

According to one embodiment, a formation process can includefunctionalization of the polyarylene sulfide. This embodiment canprovide additional sites for bonding between the impact modifier and thepolyarylene sulfide, which can further improve distribution of theimpact modifier throughout the polyarylene sulfide and further preventphase separation. Moreover, functionalization of the polyarylene sulfidecan include scission of the polyarylene sulfide chain, which candecrease the melt viscosity of the composition and improveprocessibility. This can also provide a polyarylene sulfide compositionthat is a low halogen, e.g., low chlorine composition that exhibitsexcellent physical characteristics and high resistance to degradation.

To provide further improvements to the polyarylene sulfide composition,the composition can be formed to include other conventional additivessuch as fillers, lubricants, colorants, etc. according to standardpractice.

The high strength and flexibility characteristics of the polyarylenesulfide composition can be evident by examination of the tensile,flexural, and/or impact properties of the materials. For example, thepolyarylene sulfide composition can have a notched Charpy impactstrength of greater than about 3 kJ/m², greater than about 3.5 kJ/m²,greater than about 5 kJ/m², greater than about 10 kJ/m², greater thanabout 15 kJ/m², greater than about 30 kJ/m², greater than about 33kJ/m², greater than about 40 kJ/m², greater than about 45 kJ/m², orgreater than about 50 kJ/m² as determined according to ISO Test No.179-1 (technically equivalent to ASTM D256, Method B) at 23° C. Theunnotched Charpy samples do not break under testing conditions of ISOTest No. 180 at 23° C. (technically equivalent to ASTM D256).

Beneficially, the polyarylene sulfide composition can maintain goodphysical characteristics even at extreme temperatures, including bothhigh and low temperatures. For instance, the polyarylene sulfidecomposition can have a notched Charpy impact strength of greater thanabout 8 kJ/m², greater than about 9 kJ/m², greater than about 10 kJ/m²,greater than about 14 kJ/m², greater than about 15 kJ/m², greater thanabout 18 kJ/m², or greater than about 20 kJ/m² as determined accordingto ISO Test No. 179-1 at −30° C.; and can have a notched Charpy impactstrength of greater than about 8 kJ/m², greater than about 9 kJ/m²,greater than about 10 kJ/m², greater than about 11 kJ/m², greater thanabout 12 kJ/m², or greater than about 15 kJ/m² as determined accordingto ISO Test No. 179-1 at −40° C.

Moreover, the effect of temperature change on the polyarylene sulfidecomposition can be surprisingly small. For instance, the ratio of thenotched Charpy impact strength as determined according to ISO Test No.179-1 at 23° C. to that at −30° C. can be greater than about 3.5,greater than about 3.6, or greater than about 3.7. Thus, and asdescribed in more detail in the example section below, as thetemperature increases the impact strength of the polyarylene sulfidecomposition also increases, as expected, but the rate of increase of theimpact strength is very high, particularly as compared to a compositionthat does not include the dynamically crosslinked impact modifier.Accordingly, the polyarylene sulfide composition can exhibit excellentstrength characteristics at a wide range of temperatures.

The polyarylene sulfide composition can exhibit very good tensilecharacteristics. For example, the polyarylene sulfide composition canhave a tensile elongation at yield of greater than about 4.5%, greaterthan about 6%, greater than about 7%, greater than about 10%, greaterthan about 25%, greater than about 35%, greater than about 50%, greaterthan about 70%, greater than about 75%, greater than about 80%, orgreater than about 90%. Similarly, the tensile elongation at break canbe quite high, for instance greater than about 10%, greater than about25%, greater than about 35%, greater than about 50%, greater than about70%, greater than about 75%, greater than about 80%, or greater thanabout 90%. The strain at break can be greater than about 5%, greaterthan about 15%, greater than about 20%, or greater than about 25%. Forinstance the strain at break can be about 90%. The yield strain canlikewise be high, for instance greater than about 5%, greater than about15%, greater than about 20%, or greater than about 25%. The yield stresscan be, for example, greater than about 50% or greater than about 53%.The polyarylene sulfide composition may have a tensile strength at breakof greater than about 30 MPa, greater than about 35 MPa, greater thanabout 40 MPa, greater than about 45 MPa, or greater than about 70 MPa.

In addition, the polyarylene sulfide composition can have a relativelylow tensile modulus. For instance, the polyarylene sulfide compositioncan have a tensile modulus less than about 3000 MPa, less than about2300 MPa, less than about 2000 MPa, less than about 1500 MPa, or lessthan about 1100 MPa as determined according to ISO Test No. 527 at atemperature of 23° C. and a test speed of 5 mm/min.

The polyarylene sulfide composition can exhibit good characteristicsafter annealing as well. For instance, following annealing at atemperature of about 230° C. for a period of time of about 2 hours, thetensile modulus of the composition can be less than about 2500 MPa, lessthan about 2300 MPa, or less than about 2250 MPa. The tensile strengthat break after annealing can be greater than about 50 MPa, or greaterthan about 55 MPa, as measured according to ISO Test No. 527 at atemperature of 23° C. and a test speed of 5 mm/min.

The polyarylene sulfide composition can also be utilized continuously athigh temperature, for instance at a continuous use temperature of up toabout 150° C., about 160° C., or about 165° C. without loss of tensilestrength. For example, the polyarylene sulfide composition can maintaingreater than about 95%, for instance about 100% of the original tensilestrength after 1000 hours of heat aging at 165° C. and can maintaingreater than about 95%, for instance about 100% of the original tensileelongation at yield after 1000 hours heat aging at 135° C.

Tensile characteristics can be determined according to ISO Test No. 527at a temperature of 23° C. and a test speed of 5 mm/min or 50 mm/min(technically equivalent to ASTM D623 at 23° C.).

The flexural characteristics of the composition can be determinedaccording to ISO Test No. 178 (technically equivalent to ASTM D790 at atemperature of 23° C. and a testing speed of 2 mm/min. For example, theflexural modulus of the composition can be less than about 2500 MPa,less than about 2300 MPa, less than about 2000 MPa, less than about 1800MPa, or less than about 1500 MPa. The polyarylene sulfide compositionmay have a flexural strength at break of greater than about 30 MPa,greater than about 35 MPa, greater than about 40 MPa, greater than about45 MPa, or greater than about 70 MPa.

The deflection temperature under load of the polyarylene sulfidecomposition can be relatively high. For example, the deflectiontemperature under load of the polyarylene sulfide composition can begreater than about 80° C., greater than about 90° C., greater than about100° C., or greater than about 105° C., as determined according to ISOTest No. 75-2 (technically equivalent to ASTM D790) at 1.8 MPa.

The Vicat softening point can be greater than about 200° C. or greaterthan about 250° C., for instance about 270° C. as determined accordingto the Vicat A test when a load of 10 N is used at a heating rate of 50K/hr. For the Vicat B test, when a load of 50 N is used at a heatingrate of 50 K/hr, the Vicat softening point can be greater than about100° C., greater than about 150° C. greater than about 175° C., orgreater than about 190° C., for instance about 200° C. The Vicatsoftening point can be determined according to ISO Test No. 306(technically equivalent to ASTM D1525).

The polyarylene sulfide composition can also exhibit excellent stabilityduring long term exposure to harsh environmental conditions. Forinstance, under long term exposure to an acidic environment, thepolyarylene sulfide composition can exhibit little loss in strengthcharacteristics. For instance, following 500 hours exposure to a strongacid (e.g., a solution of about 5% or more strong acid such as sulfuricacid, hydrochloric acid, nitric acid, perchloric acid, etc.), thepolyarylene sulfide composition can exhibit a loss in Charpy notchedimpact strength of less than about 17%, or less than about 16% followingexposure of about 500 hours to a strong acid solution at a temperatureof about 40° C., and can exhibit a loss in Charpy notched impactstrength of less than about 25%, or less than about 22% followingexposure of about 500 hours to a strong acid solution at a temperatureof about 80° C. Even under harsher conditions, for instance in a 10%sulfuric acid solution held at a temperature of about 80° C. for 1000hours, the polyarylene sulfide composition can maintain about 80% ormore of the initial Charpy notched impact strength. The polyarylenesulfide composition can also maintain desirable strength characteristicsfollowing exposure to other potentially degrading materials, such assalts.

Permeation resistance can be important for a wide variety ofapplications for the polyarylene sulfide composition, for instance whenutilizing the composition in formation of fuel lines, storage tanks, orthe like. The polyarylene sulfide composition can exhibit excellentpermeation resistance to a wide variety of materials. For instance, ashaped product formed of the polyarylene sulfide composition can exhibita permeation resistance to a fuel or a fuel source (e.g., gasoline,diesel fuel, jet fuel, unrefined or refined oil, etc.) of less thanabout 3 g-mm/m²-day, less than about 2 g-mm/m²-day, less than about 1g-mm/m²-day, or less than about 0.5 g-mm/m²-day. By way of example, thepolyarylene sulfide composition (or a product formed of the polyarylenesulfide composition) can exhibit a permeation resistance to an ethanolblend of ethanol/iso-octane/toluene at a weight ratio of 10:45:45 at 40°C. of less than about 3 g-mm/m²-day, less than about 2.5 g-mm/m²-day,less than about 1 g-mm/m²-day, or less than about 0.1 g-mm/m²-day. Thepermeation resistance to a blend of 15 wt. % methanol and 85 wt. %oxygenated fuel (CM15A) at 40° C. can be less than about 3 g-mm/m²-day,less than about 2.5 g-mm/m²-day, less than about 1 g-mm/m²-day, lessthan about 0.5 g-mm/m²-day, less than about 0.3 g-mm/m²-day, or lessthan about 0.15 g-mm/m²-day. The permeation resistance to methanol at40° C. can be less than about 1 g-mm/m²-day, less than about 0.5g-mm/m²-day, less than about 0.25 g-mm/m²-day, less than about 0.1g-mm/m²-day, or less than about 0.06 g-mm/m²-day. Permeation resistancecan be determined according to SAE Testing Method No. J2665. Inaddition, the polyarylene sulfide composition can maintain originaldensity following long term exposure to hydrocarbons. For example, thecomposition can maintain greater than about 95% of original density,greater than about 96% of original density, such as about 99% oforiginal density following long term (e.g., greater than about 14 days)exposure to hydrocarbons such as heptane, cyclohexane, toluene, and soforth, or combinations of hydrocarbons.

The polyarylene sulfide composition can also be resistant to uptake ofmaterials, and specifically hydrocarbons. For example, a moldedstructure formed of the composition can exhibit a volume change of lessthan about 25%, less than about 20%, or less than about 14% followingexposure to the hydrocarbon at a temperature of 130° C. for a period oftime of about two weeks.

The polyarylene sulfide composition can exhibit good heat resistance andflame retardant characteristics. For instance, the composition can meetthe V-0 flammability standard at a thickness of 0.2 millimeters. Theflame retarding efficacy may be determined according to the UL 94Vertical Burn Test procedure of the “Test for Flammability of PlasticMaterials for Parts in Devices and Appliances”, 5th Edition, Oct. 29,1996. The ratings according to the UL 94 test are listed in thefollowing table:

Afterflame Time Rating (s) Burning Drips Burn to Clamp V-0 <10 No No V-1<30 No No V-2 <30 Yes No Fail <30 Yes Fail >30 No

The “afterflame time” is an average value determined by dividing thetotal afterflame time (an aggregate value of all samples tested) by thenumber of samples. The total afterflame time is the sum of the time (inseconds) that all the samples remained ignited after two separateapplications of a flame as described in the UL-94 VTM test. Shorter timeperiods indicate better flame resistance, i.e., the flame went outfaster. For a V-0 rating, the total afterflame time for five (5)samples, each having two applications of flame, must not exceed 50seconds. Using the flame retardant of the present invention, articlesmay achieve at least a V-1 rating, and typically a V-0 rating, forspecimens having a thickness of 0.2 millimeters.

The polyarylene sulfide composition can also exhibit good processingcharacteristics, for instance as demonstrated by the melt viscosity ofthe composition. For instance, the polyarylene sulfide composition canhave a melt viscosity of less than about 2800 poise as measured on acapillary rheometer at 316° C. and 400 sec⁻¹ with the viscositymeasurement taken after five minutes of constant shear. Moreover, thepolyarylene sulfide composition can exhibit improved melt stability overtime as compared to polyarylene sulfide compositions that do not includecrosslinked impact modifiers. Polyarylene sulfide compositions that donot include a crosslinked impact modifier tend to exhibit an increase inmelt viscosity over time, and in contrast, disclosed compositions canmaintain or even decrease in melt viscosity over time.

The polyarylene sulfide composition can have a complex viscosity asdetermined at low shear (0.1 radians per second (rad/s)) and 310° C. ofgreater than about 10 kPa/sec, greater than about 25 kPa/sec, greaterthan about 40 kPa/sec, greater than about 50 kPa/sec, greater than about75 kPa/sec, greater than about 200 kPa/sec, greater than about 250kPa/sec, greater than about 300 kPa/sec, greater than about 350 kPa/sec,greater than about 400 kPa/sec, or greater than about 450 kPa/sec.Higher value for complex viscosity at low shear is indicative of thecrosslinked structure of the composition and the higher melt strength ofthe polyarylene sulfide composition. In addition, the polyarylenesulfide composition can exhibit high shear sensitivity, which indicatesexcellent characteristics for use in formation processes such as blowmolding and extrusion processing.

FIG. 7 illustrates a schematic of a process that can be used in formingthe polyarylene sulfide composition. As illustrated, the components ofthe polyarylene sulfide composition may be melt-kneaded in a meltprocessing unit such as an extruder 700. Extruder 700 can be anyextruder as is known in the art including, without limitation, a single,twin, or multi-screw extruder, a co-rotating or counter rotatingextruder, an intermeshing or non-intermeshing extruder, and so forth. Inone embodiment, the composition may be melt processed in an extruder 700that includes multiple zones or barrels. In the illustrated embodiment,extruder 700 includes 10 barrels numbered 721-730 along the length ofthe extruder 700, as shown. Each barrel 721-730 can include feed lines714, 716, vents 712, temperature controls, etc. that can beindependently operated. A general purpose screw design can be used tomelt process the polyarylene composition. By way of example, apolyarylene sulfide composition may be melt mixed using a twin screwextruder such as a Coperion co-rotating fully intermeshing twin screwextruder.

In forming a polyarylene sulfide composition, the polyarylene sulfidecan be fed to the extruder 700 at a main feed throat 714. For instance,the polyarylene sulfide may be fed to the main feed throat 714 at thefirst barrel 721 by means of a metering feeder. The polyarylene sulfidecan be melted and mixed with the other components of the composition asit progresses through the extruder 700. The impact modifier can be addedto the composition in conjunction with the polyarylene sulfidecomposition at the main feed throat 714 or downstream of the main feedthroat, as desired.

At a point downstream of the main feed throat 714, and followingaddition of the impact modifier to the composition, the crosslinkingagent can be added to the composition. For instance, in the illustratedembodiment, a second feed line 716 at barrel 726 can be utilized foraddition of the crosslinking agent. The point of addition for thecrosslinking agent is not particularly limited. However, thecrosslinking agent can be added to the composition at a point after thepolyarylene sulfide has been mixed with the impact modifier under shearsuch that the impact modifier is well distributed throughout thepolyarylene sulfide.

The polyarylene sulfide may be a polyarylene thioether containing repeatunits of the formula (I):—[(Ar¹)_(n)—X]_(m)—[(Ar²)_(i)—Y]_(j)—[(Ar³)_(k)—Z]_(l)—[(Ar⁴)_(o)—W]_(p)—  (I)wherein Ar¹, Ar², Ar³, and Ar⁴ are the same or different and are aryleneunits of 6 to 18 carbon atoms; W, X, Y, and Z are the same or differentand are bivalent linking groups selected from —SO₂—, —S—, —SO—, —CO—,—O—, —COO— or alkylene or alkylidene groups of 1 to 6 carbon atoms andwherein at least one of the linking groups is —S—; and n, m, i, j, k, l,o, and p are independently zero or 1, 2, 3, or 4, subject to the provisothat their sum total is not less than 2. The arylene units Ar¹, Ar²,Ar³, and Ar⁴ may be selectively substituted or unsubstituted.Advantageous arylene systems are phenylene, biphenylene, naphthylene,anthracene and phenanthrene. The polyarylene sulfide typically includesmore than about 30 mol %, more than about 50 mol %, or more than about70 mol % arylene sulfide (—S—) units. In one embodiment the polyarylenesulfide includes at least 85 mol % sulfide linkages attached directly totwo aromatic rings.

In one embodiment, the polyarylene sulfide is a polyphenylene sulfide,defined herein as containing the phenylene sulfide structure—(C₆H₄—S)_(n)— (wherein n is an integer of 1 or more) as a componentthereof.

The polyarylene sulfide may be synthesized prior to forming thepolyarylene sulfide composition, though this is not a requirement of aprocess, and a polyarylene sulfide can also be purchased from knownsuppliers. For instance Fortron® polyphenylene sulfide available fromTicona of Florence, Ky., USA can be purchased and utilized as thepolyarylene sulfide. In those embodiments in which the polyarylenesulfide is synthesized, synthesis techniques that may be used aregenerally known in the art. By way of example, a process for producing apolyarylene sulfide can include reacting a material that provides ahydrosulfide ion, e.g., an alkali metal sulfide, with a dihaloaromaticcompound in an organic amide solvent.

The polyarylene sulfide may be linear, semi-linear, branched orcrosslinked. A linear polyarylene sulfide includes as the mainconstituting unit the repeating unit of —(Ar—S)—. In general, a linearpolyarylene sulfide may include about 80 mol % or more of this repeatingunit. A linear polyarylene sulfide may include a small amount of abranching unit or a cross-linking unit, but the amount of branching orcross-linking units may be less than about 1 mol % of the total monomerunits of the polyarylene sulfide. A linear polyarylene sulfide polymermay be a random copolymer or a block copolymer containing theabove-mentioned repeating unit.

A semi-linear polyarylene sulfide may be utilized that may have across-linking structure or a branched structure provided by introducinginto the polymer a small amount of one or more monomers having three ormore reactive functional groups. For instance between about 1 mol % andabout 10 mol % of the polymer may be formed from monomers having threeor more reactive functional groups. Methods that may be used in makingsemi-linear polyarylene sulfide are generally known in the art.

The polyarylene sulfide composition may include the polyarylene sulfidecomponent (which also encompasses a blend of polyarylene sulfides) in anamount from about 10 wt. % to about 99 wt. % by weight of thecomposition, for instance from about 20% wt. % to about 90 wt. % byweight of the composition.

The polyarylene sulfide may be of any suitable molecular weight and meltviscosity, generally depending upon the final application intended forthe polyarylene sulfide composition. For instance, the melt viscosity ofthe polyarylene sulfide may be a low viscosity polyarylene sulfide,having a melt viscosity of less than about 500 poise, a medium viscositypolyarylene sulfide, having a melt viscosity of between about 500 poiseand about 1500 poise, or a high melt viscosity polyarylene sulfide,having a melt viscosity of greater than about 1,500 poise, as determinedin accordance with ISO Test No. 11443 at a shear rate of 1200 s⁻¹ and ata temperature of 310° C.

According to one embodiment, the polyarylene sulfide can befunctionalized to further encourage bond formation between thepolyarylene sulfide and the impact modifier. For instance, a polyarylenesulfide can be further treated following formation with a carboxyl, acidanhydride, amine, isocyanate or other functional group-containingmodifying compound to provide a functional terminal group on thepolyarylene sulfide. By way of example, a polyarylene sulfide can bereacted with a modifying compound containing a mercapto group or adisulfide group and also containing a reactive functional group. In oneembodiment, the polyarylene sulfide can be reacted with the modifyingcompound in an organic solvent. In another embodiment, the polyarylenesulfide can be reacted with the modifying compound in the molten state.

In one embodiment, a disulfide compound containing the desiredfunctional group can be incorporated into the polyarylene sulfidecomposition formation process, and the polyarylene sulfide can befunctionalized in conjunction with formation of the composition. Forinstance, a disulfide compound containing the desired reactivefunctional groups can be added to the melt extruder in conjunction withthe polyarylene sulfide or at any other point prior to or in conjunctionwith the addition of the crosslinking agent.

Reaction between the polyarylene sulfide polymer and the reactivelyfunctionalized disulfide compound can include chain scission of thepolyarylene sulfide polymer that can decrease melt viscosity of thepolyarylene sulfide. In one embodiment, a higher melt viscositypolyarylene sulfide having low halogen content can be utilized as astarting polymer. Following reactive functionalization of thepolyarylene sulfide polymer by use of a functional disulfide compound, arelatively low melt viscosity polyarylene sulfide with low halogencontent can be formed. Following this chain scission, the melt viscosityof the polyarylene sulfide can be suitable for further processing, andthe overall halogen content of the low melt viscosity polyarylenesulfide can be quite low. A polyarylene sulfide composition thatexhibits excellent strength and degradation resistance in addition tolow halogen content can be advantageous as low halogen content polymericmaterials are becoming increasingly desired due to environmentalconcerns. In one embodiment, the polyarylene sulfide composition canhave a halogen content of less than about 1000 ppm, less than about 900ppm, less than about 600 ppm, or less than about 400 ppm as determinedaccording to an elemental analysis using Parr Bomb combustion followedby Ion Chromatography.

The disulfide compound can generally have the structure of:R¹—S—S—R²wherein R¹ and R² may be the same or different and are hydrocarbongroups that independently include from 1 to about 20 carbons. Forinstance, R¹ and R² may be an alkyl, cycloalkyl, aryl, or heterocyclicgroup. R¹ and R¹ may include reactive functionality at terminal end(s)of the disulfide compound. For example, at least one of R¹ and R² mayinclude a terminal carboxyl group, hydroxyl group, a substituted ornon-substituted amino group, a nitro group, or the like. In general, thereactive functionality can be selected such that the reactivelyfunctionalized polyarylene sulfide can react with the impact modifier.For example, when considering an epoxy-terminated impact modifier, thedisulfide compound can include carboxyl and/or amine functionality.

Examples of disulfide compounds including reactive terminal groups asmay be encompassed herein may include, without limitation,2,2′-diaminodiphenyl disulfide, 3,3′-diaminodiphenyl disulfide,4,4′-diaminodiphenyl disulfide, dibenzyl disulfide, dithiosalicyclicacid, dithioglycolic acid, α,α′-dithiodilactic acid, β,β′-dithiodilacticacid, 3,3′-dithiodipyridine, 4,4′dithiomorpholine,2,2′-dithiobis(benzothiazole), 2,2′-dithiobis(benzimidazole),2,2′-dithiobis(benzoxazole) and 2-(4′-morpholinodithio)benzothiazole.

The ratio of the amount of the polyarylene sulfide to the amount of thedisulfide compound can be from about 1000:1 to about 10:1, from about500:1 to about 20:1, or from about 400:1 to about 30:1.

In addition to the polyarylene sulfide polymer, the composition alsoincludes an impact modifier. More specifically, the impact modifier canbe an olefinic copolymer or terpolymer. For instance, the impactmodifier can include ethylenically unsaturated monomer units have fromabout 4 to about 10 carbon atoms.

The impact modifier can be modified to include functionalization so asto react with the crosslinking agent. For instance, the impact modifiercan be modified with a mole fraction of from about 0.01 to about 0.5 ofone or more of the following: an α,β unsaturated dicarboxylic acid orsalt thereof having from about 3 to about 8 carbon atoms; an α,βunsaturated carboxylic acid or salt thereof having from about 3 to about8 carbon atoms; an anhydride or salt thereof having from about 3 toabout 8 carbon atoms; a monoester or salt thereof having from about 3 toabout 8 carbon atoms; a sulfonic acid or a salt thereof; an unsaturatedepoxy compound having from about 4 to about 11 carbon atoms. Examples ofsuch modification functionalities include maleic anhydride, fumaricacid, maleic acid, methacrylic acid, acrylic acid, and glycidylmethacrylate. Examples of metallic acid salts include the alkaline metaland transitional metal salts such as sodium, zinc, and aluminum salts.

A non-limiting listing of impact modifiers that may be used includeethylene-acrylic acid copolymer, ethylene-maleic anhydride copolymers,ethylene-alkyl(meth)acrylate-maleic anhydride terpolymers,ethylene-alkyl(meth)acrylate-glycidyl (meth)acrylate terpolymers,ethylene-acrylic ester-methacrylic acid terpolymer, ethylene-acrylicester-maleic anhydride terpolymer, ethylene-methacrylic acid-methacrylicacid alkaline metal salt (ionomer) terpolymers, and the like. In oneembodiment, for instance, an impact modifier can include a randomterpolymer of ethylene, methylacrylate, and glycidyl methacrylate. Theterpolymer can have a glycidyl methacrylate content of from about 5% toabout 20%, such as from about 6% to about 10%. The terpolymer may have amethylacrylate content of from about 20% to about 30%, such as about24%.

According to one embodiment, the impact modifier may be a linear orbranched, homopolymer or copolymer (e.g., random, graft, block, etc.)containing epoxy functionalization, e.g., terminal epoxy groups,skeletal oxirane units, and/or pendent epoxy groups. For instance, theimpact modifier may be a copolymer including at least one monomercomponent that includes epoxy functionalization. The monomer units ofthe impact modifier may vary. In one embodiment, for example, the impactmodifier can include epoxy-functional methacrylic monomer units. As usedherein, the term methacrylic generally refers to both acrylic andmethacrylic monomers, as well as salts and esters thereof, e.g.,acrylate and methacrylate monomers. Epoxy-functional methacrylicmonomers as may be incorporated in the impact modifier may include, butare not limited to, those containing 1,2-epoxy groups, such as glycidylacrylate and glycidyl methacrylate. Other suitable epoxy-functionalmonomers include allyl glycidyl ether, glycidyl ethacrylate, andglycidyl itoconate.

Other monomer units may additionally or alternatively be a component ofthe impact modifier. Examples of other monomers may include, forexample, ester monomers, olefin monomers, amide monomers, etc. In oneembodiment, the impact modifier can include at least one linear orbranched—olefin monomer, such as those having from 2 to 20 carbon atoms,or from 2 to 8 carbon atoms. Specific examples include ethylene;propylene; 1-butene; 3-methyl-1-butene; 3,3-dimethyl-1-butene;1-pentene; 1-pentene with one or more methyl, ethyl or propylsubstituents; 1-hexene with one or more methyl, ethyl or propylsubstituents; 1-heptene with one or more methyl, ethyl or propylsubstituents; 1-octene with one or more methyl, ethyl or propylsubstituents; 1-nonene with one or more methyl, ethyl or propylsubstituents; ethyl, methyl or dimethyl-substituted 1-decene;1-dodecene; and styrene.

Monomers included in an impact modifier that includes epoxyfunctionalization can include monomers that do not include epoxyfunctionalization, as long as at least a portion of the monomer units ofthe polymer are epoxy functionalized.

In one embodiment, the impact modifier can be a terpolymer that includesepoxy functionalization. For instance, the impact modifier can include amethacrylic component that includes epoxy functionalization, an α-olefincomponent, and a methacrylic component that does not include epoxyfunctionalization. For example, the impact modifier may bepoly(ethylene-co-methylacrylate-co-glycidyl methacrylate), which has thefollowing structure:

wherein, a, b, and c are 1 or greater.

In another embodiment the impact modifier can be a random copolymer ofethylene, ethyl acrylate and maleic anhydride having the followingstructure:

wherein x, y and z are 1 or greater.

The relative proportion of the various monomer components of acopolymeric impact modifier is not particularly limited. For instance,in one embodiment, the epoxy-functional methacrylic monomer componentscan form from about 1 wt. % to about 25 wt. %, or from about 2 wt. % toabout 20 wt % of a copolymeric impact modifier. An a-olefin monomer canform from about 55 wt. % to about 95 wt. %, or from about 60 wt. % toabout 90 wt. %, of a copolymeric impact modifier. When employed, othermonomeric components (e.g., a non-epoxy functional methacrylic monomers)may constitute from about 5 wt. % to about 35 wt. %, or from about 8 wt.% to about 30 wt. %, of a copolymeric impact modifier.

An impact modifier may be formed according to standard polymerizationmethods as are generally known in the art. For example, a monomercontaining polar functional groups may be grafted onto a polymerbackbone to form a graft copolymer. Alternatively, a monomer containingfunctional groups may be copolymerized with a monomer to form a block orrandom copolymer using known free radical polymerization techniques,such as high pressure reactions, Ziegler-Natta catalyst reactionsystems, single site catalyst (e.g., metallocene) reaction systems, etc.

Alternatively, an impact modifier may be obtained on the retail market.By way of example, suitable compounds for use as an impact modifier maybe obtained from Arkema under the name Lotader®.

The molecular weight of the impact modifier can vary widely. Forexample, the impact modifier can have a number average molecular weightfrom about 7,500 to about 250,000 grams per mole, in some embodimentsfrom about 15,000 to about 150,000 grams per mole, and in someembodiments, from about 20,000 to 100,000 grams per mole, with apolydispersity index typically ranging from 2.5 to 7.

In general, the impact modifier may be present in the composition in anamount from about 0.05% to about 40% by weight, from about 0.05% toabout 37% by weight, or from about 0.1% to about 35% by weight.

Referring again to FIG. 7, the impact modifier can be added to thecomposition in conjunction with the polyarylene sulfide composition atthe main feed throat 714 of the melt processing unit. This is not arequirement of the composition formation process, however, and in otherembodiments, the impact modifier can be added downstream of the mainfeed throat. For instance, the impact modifier may be added at alocation downstream from the point at which the polyarylene sulfide issupplied to the melt processing unit, but yet prior to the meltingsection, i.e., that length of the melt processing unit in which thepolyarylene sulfide becomes molten. In another embodiment, the impactmodifier may be added at a location downstream from the point at whichthe polyarylene sulfide becomes molten.

If desired, one or more distributive and/or dispersive mixing elementsmay be employed within the mixing section of the melt processing unit.Suitable distributive mixers for single screw extruders may include butare not limited to, for instance, Saxon, Dulmage, Cavity Transfermixers, etc. Likewise, suitable dispersive mixers may include but arenot limited to Blister ring, Leroy/Maddock, CRD mixers, etc. As is wellknown in the art, the mixing may be further improved by using pins inthe barrel that create a folding and reorientation of the polymer melt,such as those used in Buss Kneader extruders, Cavity Transfer mixers,and Vortex Intermeshing Pin mixers.

In addition to the polyarylene sulfide and the impact modifier, thepolyarylene composition can include a crosslinking agent. Thecrosslinking agent can be a polyfunctional compound or combinationthereof that can react with functionality of the impact modifier to formcrosslinks within and among the polymer chains of the impact modifier.In general, the crosslinking agent can be a non-polymeric compound,i.e., a molecular compound that includes two or more reactivelyfunctional terminal moieties linked by a bond or a non-polymeric(non-repeating) linking component. By way of example, the crosslinkingagent can include but is not limited to di-epoxides, poly-functionalepoxides, diisocyanates, polyisocyanates, polyhydric alcohols,water-soluble carbodiimides, diamines, diaminoalkanes, polyfunctionalcarboxylic acids, diacid halides, and so forth. For instance, whenconsidering an epoxy-functional impact modifier, a non-polymericpolyfunctional carboxylic acid or amine can be utilized as acrosslinking agent.

Specific examples of polyfunctional carboxylic acid crosslinking agentscan include, without limitation, isophthalic acid, terephthalic acid,phthalic acid, 1,2-di(p-carboxyphenyl)ethane, 4,4′-dicarboxydiphenylether, 4,4′-bisbenzoic acid, 1,4- or 1,5-naphthalene dicarboxylic acids,decahydronaphthalene dicarboxylic acids, norbornene dicarboxylic acids,bicyclooctane dicarboxylic acids, 1,4-cyclohexanedicarboxylic acid (bothcis and trans), 1,4-hexylenedicarboxylic acid, adipic acid, azelaicacid, dicarboxyl dodecanoic acid, succinic acid, maleic acid, glutaricacid, suberic acid, azelaic acid and sebacic acid. The correspondingdicarboxylic acid derivatives, such as carboxylic acid diesters havingfrom 1 to 4 carbon atoms in the alcohol radical, carboxylic acidanhydrides or carboxylic acid halides may also be utilized.

Exemplary diols useful as crosslinking agents can include, withoutlimitation, aliphatic diols such as ethylene glycol, 1,2-propyleneglycol, 1,3-propylene glycol, 2,2-dimethyl-1,3-propane diol,2-ethyl-2-methyl-1,3-propane diol, 1,4-butane diol, 1,4-but-2-ene diol,1,3-1,5-pentane diol, 1,5-pentane diol, dipropylene glycol,2-methyl-1,5-pentane diol, and the like. Aromatic diols can also beutilized such as, without limitation, hydroquinone, catechol,resorcinol, methylhydroquinone, chlorohydroquinone, bisphenol A,tetrachlorobisphenol A, phenolphthalein, and the like. Exemplarycycloaliphatic diols as may be used include a cycloaliphatic moiety, forexample 1,6-hexane diol, dimethanol decalin, dimethanol bicyclooctane,1,4-cyclohexane dimethanol (including its cis- and trans-isomers),triethylene glycol, 1,10-decanediol, and the like.

Exemplary diamines that may be utilized as crosslinking agents caninclude, without limitation, isophorone-diamine, ethylenediamine, 1,2-,1,3-propylene-diamine, N-methyl-1,3-propylene-diamine,N,N′-dimethyl-ethylene-diamine, and aromatic diamines, such as, forexample, 2,4- and 2,6-toluoylene-diamine, 3,5-diethyl-2,4- and/or-2,6-toluoylene-diamine, and primary ortho-di-, tri- and/ortetra-alkyl-substituted 4,4′-diaminodiphenyl-methanes, (cyclo)aliphaticdiamines, such as, for example, isophorone-diamine, ethylenediamine,1,2-, 1,3-propylene-diamine, N-methyl-1,3-propylene-diamine,N,N′-dimethyl-ethylene-diamine, and aromatic diamines, such as, forexample, 2,4- and 2,6-toluoylene-diamine, 3,5-diethyl-2,4- and/or-2,6-toluoylene-diamine, and primary ortho-di-, tri- and/ortetra-alkyl-substituted 4,4′-diaminodiphenyl-methanes.

In one embodiment, the composition can include a disulfide-freecrosslinking agent. For example, the crosslinking agent can includecarboxyl and/or amine functionality with no disulfide group that mayreact with the polyarylene sulfide. A crosslinking agent that isdisulfide-free can be utilized so as to avoid excessive chain scissionof the polyarylene sulfide by the crosslinking agent during formation ofthe composition. It should be understood, however, that the utilizationof a disulfide-free crosslinking agent does not in any way limit theutilization of a reactively functionalized disulfide compound forfunctionalizing the polyarylene sulfide. For instance, in oneembodiment, the composition can be formed according to a process thatincludes addition of a reactively functionalized disulfide compound tothe melt processing unit that can reactively functionalize thepolyarylene sulfide. The crosslinking agent utilized in this embodimentcan then be a disulfide-free crosslinking agent that can includefunctionality that is reactive with the impact modifier as well as withthe reactively functionalized polyarylene sulfide. Thus, the compositioncan be highly crosslinked without excessive scission of the polyarylenesulfide polymer chains.

In another embodiment the crosslinking agent and the polyarylene sulfidefunctionalization compound (when present) can be selected so as toencourage chain scission of the polyarylene sulfide. This may bebeneficial, for instance, which chain scission is desired to decreasethe melt viscosity of the polyarylene sulfide polymer.

The polyarylene sulfide composition may generally include thecrosslinking agent in an amount from about 0.05 wt. % to about 2 wt. %by weight of the polyarylene sulfide composition, from about 0.07 wt. %to about 1.5 wt. % by weight of the polyarylene sulfide composition, orfrom about 0.1 wt. % to about 1.3 wt. %.

The crosslinking agent can be added to the melt processing unitfollowing mixing of the polyarylene sulfide and the impact modifier. Forinstance, as illustrated in FIG. 7, the crosslinking agent can be addedto the composition at a downstream location 716 following addition ofpolyarylene sulfide and the impact modifier (either together orseparately) to the melt processing unit. This can ensure that the impactmodifier has become dispersed throughout the polyarylene sulfide priorto addition of the crosslinking agent.

To help encourage distribution of the impact modifier throughout themelt prior to addition of the crosslinking agent, a variety of differentparameters may be selectively controlled. For example, the ratio of thelength (“L”) to diameter (“D”) of a screw of the melt processing unitmay be selected to achieve an optimum balance between throughput andimpact modifier distribution. For example, the L/D value after the pointat which the impact modifier is supplied may be controlled to encouragedistribution of the impact modifier. More particularly, the screw has ablending length (“L_(B)”) that is defined from the point at which boththe impact modifier and the polyarylene sulfide are supplied to the unit(i.e., either where they are both supplied in conjunction with oneanother or the point at which the latter of the two is supplied) to thepoint at which the crosslinking agent is supplied, the blending lengthgenerally being less than the total length of the screw. For example,when considering a melt processing unit that has an overall L/D of 40,the L_(B)/D ratio of the screw can be from about 1 to about 36, in someembodiments from about 4 to about 20, and in some embodiments, fromabout 5 to about 15. In one embodiment, the L/L_(B) ratio can be fromabout 40 to about 1.1, from about 20 to about 2, or from about 10 toabout 5.

Following addition of the crosslinking agent, the composition can bemixed to distribute the crosslinking agent throughout the compositionand encourage reaction between the crosslinking agent, the impactmodifier, and, in one embodiment, with the polyarylene sulfide.

The composition can also include one or more additives as are generallyknown in the art. For example, one or more fillers can be included inthe polyarylene sulfide composition. One or more fillers may generallybe included in the polyarylene sulfide composition an amount of fromabout 5 wt. % to about 70 wt. %, or from about 20 wt. % to about 65 wt.% by weight of the polyarylene sulfide composition.

The filler can be added to the polyarylene sulfide composition accordingto standard practice. For instance, the filler can be added to thecomposition at a downstream location of the melt processing unit. Forexample, a filler may be added to the composition in conjunction withthe addition of the crosslinking agent. However, this is not arequirement of a formation process and the filler can be addedseparately from the crosslinking agent and either upstream or downstreamof the point of addition of the crosslinking agent. In addition, afiller can be added at a single feed location, or may be split and addedat multiple feed locations along the melt processing unit.

In one embodiment, a fibrous filler can be included in the polyarylenesulfide composition. The fibrous filler may include one or more fibertypes including, without limitation, polymer fibers, glass fibers,carbon fibers, metal fibers, basalt fibers, and so forth, or acombination of fiber types.

In one embodiment, the fibers may be chopped fibers, continuous fibers,or fiber rovings (tows).

Fiber sizes can vary as is known in the art. In one embodiment, thefibers can have an initial length of from about 3 mm to about 5 mm. Inanother embodiment, for instance when considering a pultrusion process,the fibers can be continuous fibers. Fiber diameters can vary dependingupon the particular fiber used. The fibers, for instance, can have adiameter of less than about 100 μm, such as less than about 50 μm. Forinstance, the fibers can be chopped or continuous fibers and can have afiber diameter of from about 5 μm to about 50 μm, such as from about 5μm to about 15 μm.

The fibers may be pretreated with a sizing as is generally known. In oneembodiment, the fibers may have a high yield or small K numbers. The towis indicated by the yield or K number. For instance, glass fiber towsmay have 50 yield and up, for instance from about 115 yield to about1200 yield.

Other fillers can alternatively be utilized or may be utilized inconjunction with a fibrous filler. For instance, a particulate fillercan be incorporated in the polyarylene sulfide composition. In general,particulate fillers can encompass any particulate material having amedian particle size of less than about 750 μm, for instance less thanabout 500 μm, or less than about 100 μm. In one embodiment, aparticulate filler can have a median particle size in the range of fromabout 3 μm to about 20 μm. In addition, a particulate filler can besolid or hollow, as is known. Particulate fillers can also include asurface treatment, as is known in the art.

Particulate fillers can encompass one or more mineral fillers. Forinstance, the polyarylene sulfide composition can include one or moremineral fillers in an amount of from about 1 wt. % to about 60 wt. % ofthe composition. Mineral fillers may include, without limitation,silica, quartz powder, silicates such as calcium silicate, aluminumsilicate, kaolin, talc, mica, clay, diatomaceous earth, wollastonite,calcium carbonate, and so forth.

When incorporating multiple fillers, for instance a particulate fillerand a fibrous filler, the fillers may be added together or separately tothe melt processing unit. For instance, a particulate filler can beadded to the main feed with the polyarylene sulfide or downstream priorto addition of a fibrous filler, and a fibrous filler can be addedfurther downstream of the addition point of the particulate filler. Ingeneral, a fibrous filler can be added downstream of any other fillerssuch as a particulate filler, though this is not a requirement.

A filler can be an electrically conductive filler such as, withoutlimitation, carbon black, graphite, graphene, carbon fiber, carbonnanotubes, a metal powder, and so forth. In those embodiments in whichthe polyarylene sulfide composition includes electrically conductivefillers, for instance when the polyarylene sulfide composition isutilized in forming a fuel line, adequate electrically conductive fillercan be included such that the composition has a volume specificresistance of equal to or less than about 10⁹ ohms cm.

In one embodiment, the polyarylene sulfide composition can include a UVstabilizer as an additive. For instance, the polyarylene sulfidecomposition can include a UV stabilizer in an amount of between about0.5 wt. % and about 15 wt. %, between about 1 wt. % and about 8 wt. %,or between about 1.5 wt. % and about 7 wt. % of a UV stabilizer. Oneparticularly suitable UV stabilizer that may be employed is a hinderedamine UV stabilizer. Suitable hindered amine UV stabilizer compounds maybe derived from a substituted piperidine, such as alkyl-substitutedpiperidyl, piperidinyl, piperazinone, alkoxypiperidinyl compounds, andso forth. For example, the hindered amine may be derived from a2,2,6,6-tetraalkylpiperidinyl. The hindered amine may, for example, bean oligomeric or polymeric compound having a number average molecularweight of about 1,000 or more, in some embodiments from about 1000 toabout 20,000, in some embodiments from about 1500 to about 15,000, andin some embodiments, from about 2000 to about 5000. Such compoundstypically contain at least one 2,2,6,6-tetraalkylpiperidinyl group(e.g., 1 to 4) per polymer repeating unit. One particularly suitablehigh molecular weight hindered amine is commercially available fromClariant under the designation Hostavin® N30 (number average molecularweight of 1200). Another suitable high molecular weight hindered amineis commercially available from Adeka Palmarole SAS under the designationADK STAB® LA-63 and ADK STAB® LA-68.

In addition to the high molecular hindered amines, low molecular weighthindered amines may also be employed. Such hindered amines are generallymonomeric in nature and have a molecular weight of about 1000 or less,in some embodiments from about 155 to about 800, and in someembodiments, from about 300 to about 800.

Other suitable UV stabilizers may include UV absorbers, such asbenzotriazoles or benzopheones, which can absorb UV radiation.

An additive that may be included in a polyarylene sulfide composition isone or more colorants as are generally known in the art. For instance,the polyarylene sulfide composition can include from about 0.1 wt. % toabout 10 wt. %, or from about 0.2 wt. % to about 5 wt. % of one or morecolorants. As utilized herein, the term “colorant” generally refers toany substance that can impart color to a material. Thus, the term“colorant” encompasses both dyes, which exhibit solubility in an aqueoussolution, and pigments, that exhibit little or no solubility in anaqueous solution.

Examples of dyes that may be used include, but are not limited to,disperse dyes. Suitable disperse dyes may include those described in“Disperse Dyes” in the Color Index, 3^(rd) edition. Such dyes include,for example, carboxylic acid group-free and/or sulfonic acid group-freenitro, amino, aminoketone, ketoninime, methine, polymethine,diphenylamine, quinoline, benzimidazole, xanthene, oxazine and coumarindyes, anthraquinone and azo dyes, such as mono- or di-azo dyes. Dispersedyes also include primary red color disperse dyes, primary blue colordisperse dyes, and primary yellow color dyes.

Pigments that can be incorporated in a polyarylene sulfide compositioncan include, without limitation, organic pigments, inorganic pigments,metallic pigments, phosphorescent pigments, fluorescent pigments,photochromic pigments, thermochromic pigments, iridescent pigments, andpearlescent pigments. The specific amount of pigment can depends uponthe desired final color of the product. Pastel colors are generallyachieved with the addition of titanium dioxide white or a similar whitepigment to a colored pigment.

Other additives that can be included in the polyarylene sulfidecomposition can encompass, without limitation, antimicrobials,lubricants, pigments or other colorants, impact modifiers, antioxidants,stabilizers (e.g., heat stabilizers including organophosphites such asDoverphos® products available from Dover Chemical Corporation),surfactants, flow promoters, solid solvents, and other materials addedto enhance properties and processability. Such optional materials may beemployed in the polyarylene sulfide composition in conventional amountsand according to conventional processing techniques, for instancethrough addition to the polyarylene sulfide composition at the main feedthroat. Beneficially, the polyarylene sulfide composition can exhibitdesirable characteristics without the addition of plasticizers. Forinstance, the composition can be free of plasticizers such as phthalateesters, trimellitates, sebacates, adipates, gluterates, azelates,maleates, benzoates, and so forth.

Following addition of all components to the polyarylene sulfidecomposition, the composition is thoroughly mixed in the remainingsection(s) of the extruder and extruded through a die. The finalextrudate can be pelletized or otherwise shaped as desired, for instancethe final extrudate can be in the form of a pultruded tape or ribbon.

Conventional shaping processes can be used for forming a barrier layerout of the polyarylene sulfide composition including, withoutlimitation, extrusion, injection molding, thermoforming, compressionmolding, hot-stamping, and so forth.

At least a barrier layer for a pipe as may be utilized for carryingliquids or gases, and in one particular embodiment heated liquids orgases, may be formed from the polyarylene sulfide composition. The pipemay be single-layered or multi-layered. Typical conventional extrusionor molding processes may be used for forming the pipe. For instance,either single or multi-screw extruders may be used for extrusion of apipe layer.

A barrier layer can be formed according to an extrusion process. Forexample, an extrusion process utilizing a simple or barrier type screwcan be utilized and, in one embodiment, a mixing tip need not beutilized in the process. The compression ratio for an extrusion processcan be between about 2.5:1 and about 4:1. For instance, the compressionratio can be about 25% feed, about 25% transition, and about 50%metering. The ratio of the barrel length to the barrel diameter (L/D)can be from about 16 to about 24. An extrusion process can also utilizeother standard components as are known in the art such as, for example,breaker plates, screen packs, adapters, a die, and a vacuum tank. Thevacuum tank can generally include a sizing sleeve/calibration ring, tankseals, and the like.

When forming a barrier layer according to an extrusion process, thepolyarylene sulfide composition can first be dried, for instance at atemperature of from about 90° C. to about 100° C. for about three hours.It may be beneficial to avoid drying for an extensive length of time soas to avoid discoloration of the composition. The extruder can exhibitdifferent temperatures in different zones, as is known. For instance, inone embodiment, the extruder can include at least four zones, with thetemperature of the first zone from about 276° C. to about 288° C., thetemperature of the second zone from about 282° C. to about 299° C., thetemperature of the third zone from about 282° C. to about 299° C., andthe temperature of the fourth zone from about 540° C. to about 580° C.Meanwhile, the temperature of the die can be from about 293° C. to about310° C., and the vacuum tank water can be from about 20° C. to about 50°C.

Typically, the head pressure can be from about 100 pounds per squareinch (psi) (about 690 kPa) to about 1000 psi (about 6900 kPa), and thehead pressure can be adjusted to achieve a stable melt flow, as isknown. For instance, the head pressure can be reduced by increasing theextruder zone temperature, by increasing the extruder screw rotationsper minute, reducing the screen pack mesh size and/or the number ofscreens, and so forth. In general, the line speed can be from about 4meters per minute to about 15 meters per minute. Of course, the actualline speed can depend upon the final dimension of the final product, theaesthetics of the final product and process stability.

The die swell during an extrusion process can generally be negligible. Adraw down of about 1.2 to about 1.7 can generally be utilized, as ahigher draw down can negatively affect the final properties of theproduct, depending on other processing conditions. Die drool cangenerally be avoided by drying the resin adequately prior to extrusionas well as by maintaining the melt temperature at less than about 304°C.

In one embodiment, a barrier layer of a pipe extruded from thepolyarylene sulfide composition can have a wall thickness of betweenabout 0.5 millimeters to about 5 millimeters, though barrier layershaving larger wall thickness can be formed from the composition asdesired. The calibration ring inner diameter can decide the outerdiameter of the barrier layer and will generally be less than the outerdiameter of the die, as is known. The inner diameter of the barrierlayer can be utilized to determine the desired outer diameter of themandrel and the line speed, as is known.

Referring again to FIGS. 3 and 4, a barrier layer 120 can be formed of atape, such as a tape 152 or tape 156 as discussed with regard to FIG. 8below, formed from the polyarylene sulfide composition, which inexemplary embodiments is fiber reinforced. The tape may be wrappedaround hollow body 102 to surround the hollow body 102. For example, insome exemplary embodiments, the tape may be wrapped around the hollowbody 102 generally helically with respect to the longitudinal axis 110of the hollow body 102.

A tape may be formed using any suitable process or apparatus. Exemplaryembodiments of suitable processes and apparatus, such as pultrusionprocesses and apparatus, for forming a tape that may be a barrier layer120 according to the present disclosure are discussed in detail below.

Referring to FIG. 8, one embodiment of such an extrusion device isshown. More particularly, the apparatus includes an extruder 130containing a screw shaft 134 mounted inside a barrel 132. A heater 136(e.g., electrical resistance heater) is mounted outside the barrel 132.During use, a feedstock 137 is supplied to the extruder 130 through ahopper 138. The feedstock is formed from the polyarylene sulfidecomposition. The feedstock 137 is conveyed inside the barrel 132 by thescrew shaft 134 and heated by frictional forces inside the barrel 132and by the heater 136. Upon being heated, the feedstock 137 exits thebarrel 132 through a barrel flange 138 and enters a die flange 139 of animpregnation die 150.

A continuous fiber roving 142 or a plurality of continuous fiber rovings142 are supplied from a reel or reels 144 to die 150. The rovings 142are generally positioned side-by-side, with minimal to no distancebetween neighboring rovings, before impregnation. The feedstock 137 mayfurther be heated inside the die by heaters 146 mounted in or around thedie 150. The die is generally operated at temperatures that aresufficient to cause and/or maintain the proper melt temperature for thepolyarylene sulfide composition, thus allowing for the desired level ofimpregnation of the rovings by the polyarylene sulfide composition.Typically, the operation temperature of the die is higher than the melttemperature of the polyarylene sulfide composition, such as attemperatures from about 200° C. to about 450° C. When processed in thismanner, the continuous fiber rovings 142 become embedded in thepolyarylene sulfide composition, which may be a resin 214 processed fromthe feedstock 137. The mixture may then exit the impregnation die 150 aswetted composite, extrudate, or tape 152.

As used herein, the term “roving” generally refers to a bundle ofindividual fibers 300. The fibers 300 contained within the roving can betwisted or can be straight. The rovings may contain a single fiber typeor different types of fibers 300. Different fibers may also be containedin individual rovings or, alternatively, each roving may contain adifferent fiber type. The continuous fibers employed in the rovingspossess a high degree of tensile strength relative to their mass. Forexample, the ultimate tensile strength of the fibers is typically fromabout 1,000 to about 15,000 Megapascals (“MPa”), in some embodimentsfrom about 2,000 MPa to about 10,000 MPa, and in some embodiments, fromabout 3,000 MPa to about 6,000 MPa. Such tensile strengths may beachieved even though the fibers are of a relatively light weight, suchas a mass per unit length of from about 0.05 to about 2 grams per meter,in some embodiments from about 0.4 to about 1.5 grams per meter. Theratio of tensile strength to mass per unit length may thus be about1,000 Megapascals per gram per meter (“MPa/g/m”) or greater, in someembodiments about 4,000 MPa/g/m or greater, and in some embodiments,from about 5,500 to about 20,000 MPa/g/m. Such high strength fibers may,for instance, be metal fibers, glass fibers (e.g., E-glass, A-glass,C-glass, D-glass, AR-glass, R-glass, S-glass such as S1-glass orS2-glass, etc.), carbon fibers (e.g., amorphous carbon, graphiticcarbon, or metal-coated carbon, etc.), boron fibers, ceramic fibers(e.g., alumina or silica), aramid fibers (e.g., Kevlar® marketed by E.I. duPont de Nemours, Wilmington, Del.), synthetic organic fibers (e.g.,polyamide, polyethylene, paraphenylene, terephthalamide, polyethyleneterephthalate and polyphenylene sulfide), and various other natural orsynthetic inorganic or organic fibrous materials known for reinforcingthermoplastic and/or thermoset compositions. Carbon fibers areparticularly suitable for use as the continuous fibers, which typicallyhave a tensile strength to mass ratio in the range of from about 5,000to about 7,000 MPa/g/m. The continuous fibers often have a nominaldiameter of about 4 to about 35 micrometers, and in some embodiments,from about 9 to about 35 micrometers. The number of fibers contained ineach roving can be constant or vary from roving to roving. Typically, aroving contains from about 1,000 fibers to about 50,000 individualfibers, and in some embodiments, from about 5,000 to about 30,000fibers.

A pressure sensor 147 may sense the pressure near the impregnation die150 to allow control to be exerted over the rate of extrusion bycontrolling the rotational speed of the screw shaft 134, or the feedrate of the feeder. That is, the pressure sensor 147 is positioned nearthe impregnation die 150, such as upstream of the manifold assembly 220,so that the extruder 130 can be operated to deliver a correct amount ofresin 214 for interaction with the fiber rovings 142. After leaving theimpregnation die 150, impregnated rovings 142 or the extrudate or tape152, which may comprises the fiber impregnated polyarylene sulfidecomposition, may enter an optional pre-shaping or guiding section (notshown) and/or a preheating device to control the temperature of theextrudate before entering a nip formed between two adjacent rollers 190.Although optional, the rollers 190 can help to consolidate theimpregnated rovings 142 into a tape 156 or consolidate the tape 152 intoa final tape 156, as well as enhance fiber impregnation and squeeze outany excess voids. In addition to the rollers 190, other shaping devicesmay also be employed, such as a die system. Regardless, the resultingconsolidated tape 156 is pulled by tracks 162 and 164 mounted onrollers. The tracks 162 and 164 also pull the impregnated rovings 142 ortape 152 from the impregnation die 150 and through the rollers 190. Ifdesired, the consolidated tape 156 may be wound up at a section 171.Generally speaking, the resulting tapes are relatively thin andtypically have a thickness of from about 0.05 to about 1 millimeter, insome embodiments from about 0.1 to about 0.8 millimeters, and in someembodiments, from about 0.1 to about 0.4 millimeters.

Perspective views of one embodiment of a die 150 according to thepresent disclosure are further shown in FIGS. 8 and 9. As shown, resin214 is flowed into the die 150 as indicated by resin flow direction 244.The resin 214 is distributed within the die 150 and then interacted withthe rovings 142. The rovings 142 are traversed through the die 150 inroving run direction 282, and are coated with resin 214. The rovings 142are then impregnated with the resin 214, and these impregnated rovings142 exit the die 150. In some embodiments, as shown in FIG. 10, theimpregnated rovings 142 are connected by the resin 214 and thus exist astape 152. In other embodiments, as shown in FIGS. 9 and 10, theimpregnated rovings 142 exit the die separately, each impregnated withinresin 214.

Within the impregnation die, it is generally desired that the rovings142 are traversed through an impregnation zone 250 to impregnate therovings with the polymer resin 214. In the impregnation zone 250, thepolymer resin may be forced generally transversely through the rovingsby shear and pressure created in the impregnation zone 250, whichsignificantly enhances the degree of impregnation. This is particularlyuseful when forming a composite from tapes of a high fiber content, suchas about 35% weight fraction (“Wf”) or more, and in some embodiments,from about 40% Wf or more. Typically, the die 150 will include aplurality of contact surfaces 252, such as for example at least 2, atleast 3, from 4 to 7, from 2 to 20, from 2 to 30, from 2 to 40, from 2to 50, or more contact surfaces 252, to create a sufficient degree ofpenetration and pressure on the rovings 142. Although their particularform may vary, the contact surfaces 252 typically possess a curvilinearsurface, such as a curved lobe, pin, etc. The contact surfaces 252 arealso typically made of a metal material.

FIG. 10 shows a cross-sectional view of an impregnation die 150. Asshown, the impregnation die 150 includes a manifold assembly 220 and animpregnation section. The impregnation section includes an impregnationzone 250. In some embodiments, the impregnation section additionallyincludes a gate passage 270. The manifold assembly 220 is provided forflowing the polymer resin 214 therethrough. For example, the manifoldassembly 220 may include a channel 222 or a plurality of channels 222.The resin 214 provided to the impregnation die 150 may flow through thechannels 222.

As shown in FIG. 11, in exemplary embodiments, at least a portion ofeach of the channels 222 may be curvilinear. The curvilinear portionsmay allow for relatively smooth redirection of the resin 214 in variousdirections to distribute the resin 214 through the manifold assembly220, and may allow for relatively smooth flow of the resin 214 throughthe channels 222. Alternatively, the channels 222 may be linear, andredirection of the resin 214 may be through relatively sharp transitionareas between linear portions of the channels 222. It should further beunderstood that the channels 222 may have any suitable shape, size,and/or contour.

The plurality of channels 222 may, in exemplary embodiments as shown inFIG. 11, be a plurality of branched runners 222. The runners 222 mayinclude a first branched runner group 232. The first branched runnergroup 232 includes a plurality of runners 222 branching off from aninitial channel or channels 222 that provide the resin 214 to themanifold assembly 220. The first branched runner group 232 may include2, 3, 4 or more runners 222 branching off from the initial channels 222.

If desired, the runners 222 may include a second branched runner group234 diverging from the first branched runner group 232, as shown. Forexample, a plurality of runners 222 from the second branched runnergroup 234 may branch off from one or more of the runners 222 in thefirst branched runner group 232. The second branched runner group 234may include 2, 3, 4 or more runners 222 branching off from runners 222in the first branched runner group 232.

If desired, the runners 222 may include a third branched runner group236 diverging from the second branched runner group 234, as shown. Forexample, a plurality of runners 222 from the third branched runner group236 may branch off from one or more of the runners 222 in the secondbranched runner group 234. The third branched runner group 236 mayinclude 2, 3, 4 or more runners 222 branching off from runners 222 inthe second branched runner group 234.

In some exemplary embodiments, as shown, the plurality of branchedrunners 222 has a symmetrical orientation along a central axis 224. Thebranched runners 222 and the symmetrical orientation thereof generallyevenly distribute the resin 214, such that the flow of resin 214 exitingthe manifold assembly 220 and coating the rovings 142 is substantiallyuniformly distributed on the rovings 142. This desirably allows forgenerally uniform impregnation of the rovings 142.

Further, the manifold assembly 220 may in some embodiments define anoutlet region 242. The outlet region 242 is that portion of the manifoldassembly 220 wherein resin 214 exits the manifold assembly 220. Thus,the outlet region 242 generally encompasses at least a downstreamportion of the channels or runners 222 from which the resin 214 exits.In some embodiments, as shown, at least a portion of the channels orrunners 222 disposed in the outlet region 242 have an increasing area ina flow direction 244 of the resin 214. The increasing area allows fordiffusion and further distribution of the resin 214 as the resin 214flows through the manifold assembly 220, which further allows forsubstantially uniform distribution of the resin 214 on the rovings 142.Additionally or alternatively, various channels or runners 222 disposedin the outlet region 242 may have constant areas in the flow direction244 of the resin 214, or may have decreasing areas in the flow direction244 of the resin 214.

In some embodiments, as shown, each of the channels or runners 222disposed in the outlet region 242 is positioned such that resin 214flowing therefrom is combined with resin 214 from other channels orrunners 222 disposed in the outlet region 242. This combination of theresin 214 from the various channels or runners 222 disposed in theoutlet region 242 produces a generally singular and uniformlydistributed flow of resin 214 from the manifold assembly 220 tosubstantially uniformly coat the rovings 142. Alternatively, variouschannels or runners 222 disposed in the outlet region 242 may bepositioned such that resin 214 flowing therefrom is discrete from theresin 214 from other channels or runners 222 disposed in the outletregion 242. In these embodiments, a plurality of discrete but generallyevenly distributed resin flows 214 may be produced by the manifoldassembly 220 for substantially uniformly coating the rovings 142.

As shown in FIG. 10, at least a portion of the channels or runners 222disposed in the outlet region 242 have curvilinear cross-sectionalprofiles. These curvilinear profiles allow for the resin 214 to begradually directed from the channels or runners 222 generally downwardtowards the rovings 142. Alternatively, however, these channels orrunners 222 may have any suitable cross-sectional profiles.

As further illustrated in FIGS. 10 and 11, after flowing through themanifold assembly 220, the resin 214 may flow through gate passage 270.Gate passage 270 is positioned between the manifold assembly 220 and theimpregnation zone 250, and is provided for flowing the resin 214 fromthe manifold assembly 220 such that the resin 214 coats the rovings 142.Thus, resin 214 exiting the manifold assembly 220, such as throughoutlet region 242, may enter gate passage 270 and flow therethrough.

In some embodiments, as shown in FIG. 10, the gate passage 270 extendsvertically between the manifold assembly 220 and the impregnation zone250. Alternatively, however, the gate passage 270 may extend at anysuitable angle between vertical and horizontal such that resin 214 isallowed to flow therethrough.

Further, as shown in FIG. 10, in some embodiments at least a portion ofthe gate passage 270 has a decreasing cross-sectional profile in theflow direction 244 of the resin 214. This taper of at least a portion ofthe gate passage 270 may increase the flow rate of the resin 214 flowingtherethrough before it contacts the rovings 142, which may allow theresin 214 to impinge on the rovings 142. Initial impingement of therovings 142 by the resin 214 provides for further impregnation of therovings, as discussed below. Further, tapering of at least a portion ofthe gate passage 270 may increase backpressure in the gate passage 270and the manifold assembly 220, which may further provide more even,uniform distribution of the resin 214 to coat the rovings 142.Alternatively, the gate passage 270 may have an increasing or generallyconstant cross-sectional profile, as desired or required.

Upon exiting the manifold assembly 220 and the gate passage 270 of thedie 150 as shown in FIG. 10, the resin 214 contacts the rovings 142being traversed through the die 150. As discussed above, the resin 214may substantially uniformly coat the rovings 142, due to distribution ofthe resin 214 in the manifold assembly 220 and the gate passage 270.Further, in some embodiments, the resin 214 may impinge on an uppersurface of each of the rovings 142, or on a lower surface of each of therovings 142, or on both an upper and lower surface of each of therovings 142. Initial impingement on the rovings 142 provides for furtherimpregnation of the rovings 142 with the resin 214. Impingement on therovings 142 may be facilitated by the velocity of the resin 214 when itimpacts the rovings 142, the proximity of the rovings 142 to the resin214 when the resin exits the manifold assembly 220 or gate passage 270,or other various variables.

As shown in FIG. 10, the coated rovings 142 are traversed in rundirection 282 through impregnation zone 250. The impregnation zone 250is in fluid communication with the manifold assembly 220, such asthrough the gate passage 270 disposed therebetween. The impregnationzone 250 is configured to impregnate the rovings 142 with the resin 214.

For example, as discussed above, in exemplary embodiments as shown inFIGS. 10 and 12 through 14, the impregnation zone 250 includes aplurality of contact surfaces 252. The rovings 142 are traversed overthe contact surfaces 252 in the impregnation zone. Impingement of therovings 142 on the contact surface 252 creates shear and pressuresufficient to impregnate the rovings 142 with the resin 214 coating therovings 142.

In some embodiments, as shown in FIGS. 10, 13 and 14, the impregnationzone 250 is defined between two spaced apart opposing impregnationplates 256 and 258, which may be included in the impregnation section.First plate 256 defines a first inner surface 257, while second plate258 defines a second inner surface 259. The impregnation zone 250 isdefined between the first plate 256 and the second plate 258. Thecontact surfaces 252 may be defined on or extend from both the first andsecond inner surfaces 257 and 259, or only one of the first and secondinner surfaces 257 and 259.

In exemplary embodiments, as shown in FIGS. 10, 13 and 14, the contactsurfaces 252 may be defined alternately on the first and second surfaces257 and 259 such that the rovings alternately impinge on contactsurfaces 252 on the first and second surfaces 257 and 259. Thus, therovings 142 may pass contact surfaces 252 in a waveform, tortuous orsinusoidual-type pathway, which enhances shear.

Angle 254 at which the rovings 142 traverse the contact surfaces 252 maybe generally high enough to enhance shear and pressure, but not so highto cause excessive forces that will break the fibers. Thus, for example,the angle 254 may be in the range between approximately 1° andapproximately 30°, and in some embodiments, between approximately 5° andapproximately 25°.

As stated above, contact surfaces 252 typically possess a curvilinearsurface, such as a curved lobe, pin, etc. In exemplary embodiments asshown, a plurality of peaks, which may form contact surfaces 252, andvalleys are thus defined. Further, in many exemplary embodiments, theimpregnation zone 250 has a waveform cross-sectional profile. In oneexemplary embodiment as shown in FIGS. 10 and 12 through 14, the contactsurfaces 252 are lobes that form portions of the waveform surfaces ofboth the first and second plates 256 and 258 and define the waveformcross-sectional profile. FIG. 12 illustrates the second plate 258 andthe various contact surfaces thereon that form at least a portion of theimpregnation zone 250 according to some of these embodiments.

In other embodiments, the contact surfaces 252 are lobes that formportions of a waveform surface of only one of the first or second plate256 or 258. In these embodiments, impingement occurs only on the contactsurfaces 252 on the surface of the one plate. The other plate maygenerally be flat or otherwise shaped such that no interaction with thecoated rovings occurs.

In other alternative embodiments, the impregnation zone 250 may includea plurality of pins (or rods), each pin having a contact surface 252.The pins may be static, freely rotational (not shown), or rotationallydriven. Further, the pins may be mounted directly to the surface of theplates defining the impingement zone, or may be spaced from the surface.It should be noted that the pins may be heated by heaters 143, or may beheated individually or otherwise as desired or required. Further, thepins may be contained within the die 150, or may extend outwardly fromthe die 150 and not be fully encased therein.

In further alternative embodiments, the contact surfaces 252 andimpregnation zone 250 may comprise any suitable shapes and/or structuresfor impregnating the rovings 142 with the resin 214 as desired orrequired.

As discussed, a roving 142 traversed through an impregnation zone 250according to the present disclosure may become impregnated by resin 214,thus resulting in an impregnated roving 142, and optionally a tape 152comprising at least one roving 142, exiting the impregnation zone 250,such as downstream of the contact surfaces 252 in the run direction 282.The impregnated rovings 142 and optional tape 152 exiting theimpregnation zone 250 are thus formed from a fiber impregnated polymermaterial, as discussed above. At least one fiber roving 142 may becontained within a polyarylene sulfide composition resin 214, asdiscussed above, to form the fiber impregnated polyarylene sulfidecomposition and resulting tape 152 or tape 156.

As shown in FIGS. 9 and 10, in some embodiments, a faceplate 290 mayadjoin or be adjacent to the impregnation zone 250. The faceplate 290may be positioned downstream of the impregnation zone 250 and, ifincluded, the land zone 280, in the run direction 282. The faceplate 290may contact other components of the die 150, such as the impregnationzone 250 or land zone 280, or may be spaced therefrom. Faceplate 290 isgenerally configured to meter excess resin 214 from the rovings 142.Thus, apertures in the faceplate 290, through which the rovings 142traverse, may be sized such that when the rovings 142 are traversedtherethrough, the size of the apertures causes excess resin 214 to beremoved from the rovings 142.

As shown in FIG. 8, in alternative embodiments, the die 150 may lack afaceplate 290. Further, in some embodiments, the formation andmaintenance of a tape 152 within and exited from a die 150 of thepresent disclosure may be facilitated through the lack of or removal ofa faceplate from the die 150. Removal of the faceplate 290 allows for aplurality of rovings 142 exiting a die 150 to exit as a single sheet ortape 152, rather than as separated rovings 142 due to metering throughthe faceplate. This could potentially eliminate the need to later formthese rovings 142 into such a sheet or tape 156. Removal of thefaceplate 290 may have additional advantages. For example, removal mayprevent clogging of the faceplate with resin 214, which can disrupt thetraversal of rovings 142 therethrough. Additionally, removal may allowfor easier access to the impregnation zone 250, and may thus make iteasier to introduce and reintroduce rovings 142 to the impregnation zone250 during start-up, after temporary disruptions such as due to breakageof a roving 142, or during any other suitable time period.

It should be understood that a tape 152, 156 may have any suitablecross-sectional shape and/or size. For example, such tape 152, 156 mayhave a generally rectangular shape as shown in FIG. 18, or a generallyoval or circular or other suitable polygonal or otherwise shape.Further, it should be understood that one or more impregnated rovings142 having been traversed through the impregnation zone 250 may togetherform the tape 152, 156, with the resin 214 of the various rovings 142connected to form such tape 152, 156. The various above amounts, ranges,and/or ratios may thus in exemplary embodiments be determined for a tape152 having any suitable number of impregnated rovings 142 embedded andgenerally dispersed within resin 214.

To further facilitate impregnation of the rovings 142, they may also bekept under tension while present within the die 150, and specificallywithin the impregnation zone 250. The tension may, for example, rangefrom about 5 to about 300 Newtons, in some embodiments from about 50 toabout 250 Newtons, and in some embodiments, from about 100 to about 200Newtons per roving 142 or tow of fibers.

As shown in FIGS. 15 and 16, in some embodiments, a land zone 280 may bepositioned downstream of the impregnation zone 250 in run direction 282of the rovings 142. The rovings 142 may traverse through the land zone280 before exiting the die 150. In some embodiments, as shown in FIG.15, at least a portion of the land zone 280 may have an increasingcross-sectional profile in run direction 282, such that the area of theland zone 280 increases. The increasing portion may be the downstreamportion of the land zone 280 to facilitate the rovings 142 exiting thedie 150. Alternatively, the cross-sectional profile or any portionthereof may decrease, or may remain constant as shown in FIG. 16.

Additionally, other components may be optionally employed to assist inthe impregnation of the fibers. For example, a “gas jet” assembly may beemployed in certain embodiments to help uniformly spread a roving ofindividual fibers, which may each contain up to as many as 24,000fibers, across the entire width of the merged tow. This helps achieveuniform distribution of strength properties. Such an assembly mayinclude a supply of compressed air or another gas that impinges in agenerally perpendicular fashion on the moving rovings that pass acrossexit ports. The spread rovings may then be introduced into a die forimpregnation, such as described above.

It should be understood that tapes 152, 156 and impregnated rovings 142thereof according to the present disclosure need not be formed in thedies 150 and other apparatus as discussed above. Such dies 150 andapparatus are merely disclosed as examples of suitable equipment forforming tapes 152, 156. The use of any suitable equipment or process toform tapes 152, 156 is within the scope and spirit of the presentdisclosure.

The tapes 152 that result from use of the die and method may have a verylow void fraction, which helps enhance their strength. For instance, thevoid fraction may be about 3% or less, in some embodiments about 2% orless, in some embodiments about 1.5% or less, in some embodiments about1% or less, and in some embodiments, about 0.5% or less. The voidfraction may be measured using techniques well known to those skilled inthe art. For example, the void fraction may be measured using a “resinburn off” test in which samples are placed in an oven (e.g., at 600° C.for 3 hours) to burn out the resin. The mass of the remaining fibers maythen be measured to calculate the weight and volume fractions. Such“burn off” testing may be performed in accordance with ASTM D 2584-08 todetermine the weights of the fibers and the polymer matrix, which maythen be used to calculate the “void fraction” based on the followingequations:V _(f)=100*(ρ_(t)−ρ_(c))/ρ_(t)where,

V_(f) is the void fraction as a percentage;

ρ_(c) is the density of the composite as measured using knowntechniques, such as with a liquid or gas pycnometer (e.g., heliumpycnometer);

ρ_(t) is the theoretical density of the composite as is determined bythe following equation:ρ_(t)=1/[W _(f)/ρ_(f) +W _(m)/ρ_(m)]

ρ_(m) is the density of the polymer matrix (e.g., at the appropriatecrystallinity);

ρ_(f) is the density of the fibers;

W_(f) is the weight fraction of the fibers; and

W_(m) is the weight fraction of the polymer matrix.

Alternatively, the void fraction may be determined by chemicallydissolving the resin in accordance with ASTM D 3171-09. The “burn off”and “dissolution” methods are particularly suitable for glass fibers,which are generally resistant to melting and chemical dissolution. Inother cases, however, the void fraction may be indirectly calculatedbased on the densities of the polymer, fibers, and tape in accordancewith ASTM D 2734-09 (Method A), where the densities may be determinedASTM D792-08 Method A. Of course, the void fraction can also beestimated using conventional microscopy equipment.

As discussed above, after exiting an impregnation die 150, theimpregnated rovings 142 may in some embodiments form a tape 152. Thetape 152 may be consolidated into a consolidated tape 156. The number ofrovings employed in each tape 152, 156 may vary. Typically, however, atape 152, 156 will contain from 2 to 80 rovings, and in some embodimentsfrom 10 to 60 rovings, and in some embodiments, from 20 to 50 rovings.In some embodiments, it may be desired that the rovings are spaced apartapproximately the same distance from each other within the tape 152,156. In other embodiments, however, it may be desired that the rovingsare combined, such that the fibers of the rovings are generally evenlydistributed throughout the tape 152, 156, such as throughout one or moreresin rich portions and a fiber rich portion as discussed above. Inthese embodiments, the rovings may be generally indistinguishable fromeach other. Referring to FIGS. 17 and 18, for example, embodiments of atape 152 are shown that contains rovings that are combined such that thefibers are generally evenly distributed within a fiber rich portionthereof. As shown in FIG. 17, in exemplary embodiments, the fibersextend generally unidirectionally along a longitudinal axis of the tape152.

A relatively high percentage of fibers may be employed in a tape, andfiber reinforced polyarylene sulfide composition thereof, to provideenhanced strength properties. For instance, fibers typically constitutefrom about 25 wt. % to about 90 wt. %, in some embodiments from about 30wt. % to about 75 wt. %, and in some embodiments, from about 35 wt. % toabout 70 wt. % of the tape or material thereof. Likewise, polymer(s)typically constitute from about 20 wt. % to about 75 wt. %, in someembodiments from about 25 wt. % to about 70 wt. %, and in someembodiments, from about 30 wt. % to about 65 wt. % of the tape 152, 156.Such percentage of fibers may additionally or alternatively by measuredas a volume fraction. For example, in some embodiments, the fiberreinforced polyarylene sulfide composition may have a fiber volumefraction between approximately 25% and approximately 80%, in someembodiments between approximately 30% and approximately 70%, in someembodiments between approximately 40% and approximately 60%, and in someembodiments between approximately 45% and approximately 55%.

Thus, as discussed, in exemplary embodiments, a barrier layer 120according to the present disclosure may be formed from a fiberreinforced polyarylene sulfide composition tape 152, 156. Referringagain to FIG. 3, one embodiment of a pipe section 100 that canincorporate the polyarylene sulfide composition is illustrated. Asshown, the pipe section 100 has several concentric layers. The innermostlayer is the hollow body 102. The barrier layer 120 surrounds and isimmediately adjacent the hollow body 102. The barrier layer 120 isformed of the polyarylene sulfide composition and provides strength andflexibility while preventing permeation of the fluid carried by thehollow body 102 through the wall thereof. In addition, the barrier layer120 formed of the polyarylene sulfide composition can resist degradationby both the fluid carried by the hollow body 102 (e.g., the productionfluid, the injection fluid, etc.) as well as by temperature conditionsunder which the pipe is utilized.

The pipe section 100 may also include a number of other various layers,each of which may be bonded to neighboring layers or left unbonded. Forexample, the pipe section 100 may also include an outer layer 822 thatprovides an external sleeve and an external fluid barrier as well asproviding protection to the pipe section 100 from external damage dueto, e.g., abrasion or encounters with environmental materials. The outerlayer 822 can be formed of a polymeric material such as the polyarylenesulfide composition or a high density polyethylene that can resist bothmechanical damage and intrusion of seawater to the inner layers of thepipe section 100. According to one embodiment, the outer layer 822 canbe a composite material that includes a polymeric material inconjunction with a reinforcement material such as carbon fibers, carbonsteel fibers, or glass fibers.

A hoop strength layer 804 can be located external to the barrier layerto increase the ability of the pipe to withstand hoop stresses caused byforced applied to the pipe wall by a pressure differential. The hoopstrength layer can generally be a metal layer formed of, e.g., ahelically wound strip of carbon steel that can form a layer of fromabout 3 to about 7 millimeters in thickness. The hoop strength layer canresist both internal pressure and bending of the pipe. In oneembodiment, the carbon steel strip that forms the hoop strength layer804 can define an interlocking profile, for instance an S- orZ-cross-sectional configuration, such that adjacent windings interlockwith one another to form a stronger layer. In one embodiment, the hoopstrength layer can include multiple materials for added strength. Forexample, in an embodiment in which design and pressure requirements callfor higher burst strengths, a second flat metal strip can be helicallywound over the interlocked metal strips of the hoop strength layer toprovide additional strength for this layer. An intervening polymericlayer such as an anti-wear layer discussed further herein can optionallybe located between the two layers of the hoop strength layer as well.

Additional strength layers 818 and 820 can be formed of helically-woundmetal (generally carbon steel) strips. The strength layers 818 and 820can be separated from the hoop strength layer 804 and from each other bypolymeric anti-wear layers 817 and 819. The strength layers 818 and 820can provide additional hoop strength as well as axial strength to thepipe. Though the pipe section 100 includes two strength layers 818, 820,it should be understood that a pipe section may include any suitablenumber of strength layers, including no strength layers, one, two,three, or more strength layers. In general, the helically wound metalstrips of strength layers 818 and 820 will overlap but need notinterlock. As such, the strength layers 818, 820 may have a width offrom about 1 millimeter to about 5 millimeters.

The intervening anti-wear layers 817, 819 can be formed of thepolyarylene sulfide composition or alternatively can be formed of otherpolymers such as a polyamide, a high density polyethylene, or the like.In one embodiment, the anti-wear layers 817, 819 can be a compositematerial that includes unidirectional fibers, for instance carbon orglass fibers. For instance, the anti-wear layers 817, 819 can be formedof a polymer tape or fiber-reinforced polymer tape such as a pultrudedpolymer tape or ribbon that is helically wound over each strength layer.The anti-wear layers 817, 819 can prevent wear of the adjacent strengthlayers that can come about due to motion of the layers. The anti-wearlayers 817, 819 can also prevent birdcaging of the adjacent layers. Aswith the strength layers 818, 820 of the pipe section 100, the number ofanti-wear layers is not particularly limited, and a pipe section caninclude no anti-wear layers, one anti-wear layers, or multiple anti-wearlayers depending upon the depth and local environment in which the pipesection will be utilized, the fluid to be carried by the hollow body102, and so forth. The anti-wear layers 817, 819, can be relativelythin, for instance between about 0.2 and about 1.5 millimeters.

A pipe section 100 may include additional layers as are generally knownin the art. For example, a pipe section 100 may include an insulationlayer, for instance immediately internal to the outer layer 822. Aninsulation layer, when present can be formed of a foam, fibrous mat, orany other insulation material as is known. By way of example, single ormultiple layers of an insulation tape can be wound onto the outerstrength layer to form an insulation layer between the outer strengthlayer 820 and the outer layer 822.

It should be understood that the various layers surrounding the barrierlayer 120 as shown in FIG. 3 may similarly be utilized in any suitablebonded or unbonded pipe sections 100, such as those shown in FIG. 4through 6.

Embodiments of the present disclosure are illustrated by the followingexamples that are merely for the purpose of illustration of embodimentsand are not to be regarded as limiting the scope of the invention or themanner in which it may be practiced. Unless specifically indicatedotherwise, parts and percentages are given by weight.

Formation and Test Methods

Injection Molding Process: Tensile bars are injection molded to ISO527-1 specifications according to standard ISO conditions.

Melt Viscosity: All materials are dried for 1.5 hours at 150° C. undervacuum prior to testing. The melt viscosity is measured on a capillaryrheometer at 316° C. and 400 sec⁻¹ with the viscosity measurement takenafter five minutes of constant shear.

Tensile Properties: Tensile properties including tensile modulus, yieldstress, yield strain, strength at break, elongation at yield, elongationat break, etc. are tested according to ISO Test No. 527 (technicallyequivalent to ASTM D638). Modulus, strain, and strength measurements aremade on the same test strip sample having a length of 80 mm, thicknessof 10 mm, and width of 4 mm. The testing temperature is 23° C., and thetesting speeds are 5 or 50 mm/min.

Flexural Properties: Flexural properties including flexural strength andflexural modulus are tested according to ISO Test No. 178 (technicallyequivalent to ASTM D790). This test is performed on a 64 mm supportspan. Tests are run on the center portions of uncut ISO 3167multi-purpose bars. The testing temperature is 23° C. and the testingspeed is 2 mm/min.

Deflection Temperature Under Load (“DTUL”): The deflection under loadtemperature was determined in accordance with ISO Test No. 75-2(technically equivalent to ASTM D648-07). More particularly, a teststrip sample having a length of 80 mm, thickness of 10 mm, and width of4 mm was subjected to an edgewise three-point bending test in which thespecified load (maximum outer fibers stress) was 1.8 Megapascals. Thespecimen was lowered into a silicone oil bath where the temperature israised at 2° C. per minute until it deflects 0.25 mm (0.32 mm for ISOTest No. 75-2).

Notched Charpy Impact Strength: Notched Charpy properties are testedaccording to ISO Test No. ISO 179-1) (technically equivalent to ASTMD256, Method B). This test is run using a Type A notch (0.25 mm baseradius) and Type 1 specimen size (length of 80 mm, width of 10 mm, andthickness of 4 mm). Specimens are cut from the center of a multi-purposebar using a single tooth milling machine. The testing temperature is 23°C., −30° F., or −40° F. as reported below.

Unnotched Charpy Impact Strength: Unnotched Charpy properties are testedaccording to ISO Test No. 180 (technically equivalent to ASTM D256). Thetest is run using a Type 1 specimen (length of 80 mm, width of 10 mm andthickness of 4 mm). Specimens are cut from the center of a multi-purposebare using a single tooth milling machine. The testing temperature is23° C.

Izod Notched Impact Strength: Notched Izod properties are testedaccording to ISO Test No. 180 (technically equivalent to ASTM D256,Method A). This test is run using a Type A notch. Specimens are cut fromthe center of a multi-purpose bar using a single tooth milling machine.The testing temperature is 23° C.

Density and Specific Gravity: Density was determined according to ISOTest No. 1183 (technically equivalent to ASTM D792). The specimen wasweighed in air then weighed when immersed in distilled water at 23° C.using a sinker and wire to hold the specimen completely submerged asrequired.

Vicat Softening Temperature: Vicat Softening temperature was determinedaccording to method A, with a load of 10 N and according to method Bwith a load of 50 N as described in ISO Test No. 306 (technicallyequivalent to ASTM D1525), both of which utilized a heating rate of 50K/h.

Water absorption was determined according to ISO Test No. 62. The testspecimens are immersed in distilled water at 23° C. until the waterabsorption essentially ceases (23° C./sat).

Complex Viscosity: Complex viscosity is determined by a Low shear sweep(ARES) utilizing an ARES-G2 (TA Instruments) testing machine equippedwith 25 mm SS parallel plates and using TRIOS software. A dynamic strainsweep was performed on a pellet sample prior to the frequency sweep, inorder to find LVE regime and optimized testing condition. The strainsweep was done from 0.1% to 100%, at a frequency 6.28 rad/s. The dynamicfrequency sweep for each sample was obtained from 500 to 0.1 rad/s, withstrain amplitude of 3%. The gap distance was kept at 1.5 mm for pelletsamples. The temperature was set at 310° C. for all samples.

Melt strength and melt elongation is performed on ARES-G2 equipped EVFfixture. The flame bar sample was cut as shown in FIG. 19. The same areaof flame bar was used for each run, in order to keep the crystallinityof test sample same and thus to minimize the variation betweenreplicates. A transient strain was applied to each sample at 0.2/s rate.At least triplicate run was done for each sample to obtain arepresentative curve.

Permeation Resistance: The fuel permeation studies were performed onsamples according to SAE Testing Method No. J2665. For all samples,stainless-steel cups were used. Injection molded plaques with a diameterof 3 inches (7.6 centimeters) were utilized as test samples. Thethickness of each sample was measured in 6 different areas. An O-ringViton® fluoroelastomer was used as a lower gasket between cup flange andsample (Purchased from McMaster-Carr, cat#9464K57, A75). A flat Viton®fluoroelastomer (Purchased from McMaster-Carr, cat#86075K52, 1/16″thickness, A 75) was die-cut to 3 inch (7.6 cm) OD and 2.5 inch (6.35cm) ID, and used as the upper gasket between the sample and the metalscreen. The fuel, about 200 ml, was poured into the cup, the cupapparatus was assembled, and the lid was finger-tightened. This wasincubated in a 40° C. oven for 1 hour, until the vapor pressureequilibrated and the lid was tightened to a torque 15 in-lb. The fuelloss was monitored gravimetrically, daily for the first 2 weeks followedby twice a week for the rest of the testing period. A blank run was donein the same manner with an aluminum disk (7.6 cm diameter, 1.5 mmthickness) and the result was subtracted from the samples. All sampleswere measured in duplicate. The normalized permeation rate wascalculated following an equilibration period. The permeation rate foreach sample was obtained from the slope of linear regression fitting ofdaily weight loss (gm/day). The normalized permeation rate wascalculated by dividing the permeation rate by the effective permeationarea and multiplying by average thickness of specimen. The averagepermeation rates are reported.

Salt Resistance: zinc chloride resistance was tested by use of tensilebar samples immersed in a 50% aqueous solution (by weight) of zincchloride for 200 h at 23±2° C. Charpy notched impact test was thencarried out at −30° C. calcium chloride resistance was tested by use oftensile bar samples immersed in a 50% aqueous solution (by weight) ofcalcium chloride for 200 h at 60±2° C. and 200 h out of solution at60±2° C. Charpy notched impact test was then carried out at −30° C.

Hydrocarbon Volume Uptake: Absorption and diffusion testing wasperformed using the tab ends cut from supplied tensile bars. Eachmaterial was immersed in Brent crude oil, hydrocarbon/water mixture (andin a one-off test to hydrocarbon only). Rates and amounts of liquidabsorbed were measured. The hydrocarbon liquid mixture had the followingcomposition:

Volume percent (%) Composition 10 Distilled water 60 70% heptane, 20%cyclohexane and 10% Toluene balance Nitrogen

All exposure testing was conducted at 130° C. for a period of two weeksutilizing an air-circulating oven, air having been removed from the testvessel by purging with nitrogen; the test being conducted at vaporpressure.

EXAMPLE 1

Materials utilized to form the compositions included the following:

Polyarylene sulfide: Fortron® 0214 linear polyphenylene sulfideavailable from Ticona Engineering Polymers of Florence, Ky.

Impact Modifier: LOTADER® AX8840—a random copolymer of ethylene andglycidyl methacrylate available from Arkema, Inc.

Crosslinking Agent: Terephthalic Acid

Disulfide: 2,2-dithiodibenzoic acid

Lubricant: Glycolube® P available from Lonza Group Ltd.

Materials were melt mixed using a Coperion co-rotating,fully-intermeshing, twin-screw extruder with an overall L/D of 40 andten temperature control zones including one at the die. A high shearscrew design was used to compound the additives into a resin matrix. Thepolyarylene sulfide, impact modifier and lubricant were fed to the mainfeed throat in the first barrel by means of a gravimetric feeder. Uponmelting and mixing of the above ingredients, the disulfide was fed usinga gravimetric feeder at barrel 6. Materials were further mixed thenextruded through a strand die. The strands were water-quenched in a bathto solidify and granulated in a pelletizer.

Compositions of the samples are provided in Table 1, below. Amounts areprovided as weight percentages based upon the weight of the sample.

TABLE 1 Component Addition Point Sample 1 Sample 2 Lubricant main feed0.3 0.3 Disulfide barrel 6 1.0 Impact Modifier main feed 25.0 25.0Polyarylene Sulfide main feed 74.7 73.7 Total 100.0 100.0

Following formation, samples were tested for a variety of physicalcharacteristics. Results are provided in Table 2, below.

TABLE 2 Sample 1 Sample 2 Melt Viscosity (poise) 3328 4119 TensileModulus (MPa) 1826 1691 Tensile Break Stress (MPa) 43.73 44.98 TensileBreak Strain (%) 96.37 135.12 Std. Dev. 39.07 34.40 Notched CharpyImpact 61.03 53.00 Strength at 23° C. (kJ/m²)

Samples were annealed at 230° C. for 2 hours and re-tested for physicalcharacteristics. Results are provided in Table 3, below.

TABLE 3 Sample 1 Sample 2 Tensile Modulus (MPa) 1994.00 1725.00 TensileBreak Stress (MPa) 45.04 45.20 Tensile Break Strain (%) 58.01 73.76 Std.Dev. 6.60 4.78

As can be seen, Sample 2 exhibited better tensile elongation and lowermodulus before and after annealing. However, no improvement in impactstrength was seen, which is believed to be due to a chain scissionreaction between the disulfide and the polypropylene sulfide.

EXAMPLE 2

Materials as described in Example 1 were melt mixed using a Coperionco-rotating, fully-intermeshing, twin-screw extruder with an overall L/Dof 40 and ten temperature control zones including one at the die. A highshear screw design was used to compound the additives into a resinmatrix. The polyarylene sulfide, impact modifier and lubricant were fedto the main feed throat in the first barrel by means of a gravimetricfeeder. The disulfide was fed using a gravimetric feeder at variouslocations in the extruder; at the main feed throat, at barrel 4 andbarrel 6. The crosslinking agent was fed at barrel 6. Materials werefurther mixed then extruded through a strand die. The strands werewater-quenched in a bath to solidify and granulated in a pelletizer.

Comparative Samples 3 and 4 were formed of the same composition andcompounded by use of a different screw design.

TABLE 4 Addition Point 3 4 5 6 7 8 9 10 Lubricant main feed 0.3 0.3 0.30.3 0.3 0.3 0.3 0.3 Crosslinking barrel 6 — — 0.5 1.0 1.0 0.5 0.5 0.5Agent Disulfide main feed — — — — — 0.30 — — Disulfide barrel 4 — — — —— — 0.3 — Disulfide barrel 6 — — — — — — — 0.3 Impact main feed 15.015.0 15.0 15.0 10.0 15.0 15.0 15.0 Modifier Polyarylene main feed 84.784.7 84.2 83.7 88.7 83.9 83.9 83.9 Sulfide Total 100.0 100.0 100.0 100.0100.0 100.0 100.0 100.0

Following formation, tensile bars were formed and tested for a varietyof physical characteristics. Results are provided in Table 5, below.

TABLE 5 Sample Sample 3 Sample 4 Sample 5 Sample 6 Sample 7 Sample 8Sample 9 10 Melt 2423 — 2659 2749 2067 2349 2310 2763 Viscosity (poise)Density — 1.28 — 1.25 — — — — (g/cm³) Tensile 2076 2800 2177 2207 25511845 2185 2309 Modulus (MPa) Tensile 46.13 — 45.40 48.27 51.71 46.4747.16 47.65 Break Stress (MPa) Tensile 33.68 25 43.97 35.94 26.90 47.5140.85 63.85 Break Strain (%) Elongation 5.17 5 5.59 7.49 4.5 11.78 6.947.00 at Yield (%) Yield Stress 51.07 52 50.76 51.62 59.63 51.07 52.5651.88 (MPa) Notched 22.30 30 23.90 39.40 14.80 12.50 19.70 39.90 CharpyImpact Strength at 23° C. (kJ/m²) Notched 7.8 7 — 10 — — — 10.8 CharpyImpact Strength at −30° C. (kJ/m²) DTUL (° C.) — 100 — 102 — — — — MeltTemp. 280 280 280 280 280 280 280 280 (° C.) Water — 0.05 — 0.05 — — — —absorption (%) Hydrocarbon 16 — — — — — — — volume uptake (%)

Samples were annealed at 230° C. for 2 hours and re-tested for physicalcharacteristics. Results are provided in Table 6, below.

TABLE 6 Sample Sample 3 Sample 4 Sample 5 Sample 6 Sample 7 Sample 8Sample 9 10 Tensile 2383 — 2339 2279 2708 2326 2382 2491 Modulus (MPa)Tensile 52.70 — 53.96 53.11 61.10 56.74 54.81 55.25 Break Stress (MPa)Tensile 29.42 — 20.97 35.76 20.34 31.37 41.23 49.03 Break Strain (%)Std. 6.84 — 6.95 6.66 5.40 2.83 2.65 3.74 Dev.

As can be seen, the highest tensile elongation and highest impactstrength were observed for Sample 10, which includes both thecrosslinking agent and the disulfide added at the same point downstreamduring processing.

FIG. 20 illustrates the relationship of notched Charpy impact strengthover temperature change for Sample 3 and for Sample 6. As can be seen,the polyarylene sulfide composition of Sample 6 exhibits excellentcharacteristics over the entire course of the temperature change, with ahigher rate of increase in impact strength with temperature change ascompared to the comparison material.

FIG. 21 is a scanning electron microscopy image of the polyarylenesulfide used in forming the sample 3 composition (FIG. 21A) and theSample 6 composition (FIG. 21B). As can be seen, there is no clearboundary between the polyarylene sulfide and the impact modifier in thecomposition of FIG. 21B.

Tensile bar test specimens of samples 3, 6, and 10 were immersed in 10wt. % sulfuric acid for 500 hours at either 40° C. or 80° C. Tensileproperties and impact properties were measured before and after the acidexposure. Results are summarized in Table 7 below.

TABLE 7 Sample 3 Sample 6 Sample 10 Initial properties Tensile Modulus(MPa) 2076 2207 2309 Tensile Break Stress (MPa) 46.13 48.27 47.65Tensile Break Strain (%) 33.68 35.94 63.85 Charpy notched impact 22.3039.40 39.90 strength at 23° C. (kJ/m²) Properties after 500 hoursexposure in sulfuric acid at 40° C. Tensile Modulus (MPa) 2368 2318 2327Tensile Break Stress (MPa) 48.83 48.48 48.53 Tensile Break Strain (%)10.99 28.28 30.05 Charpy notched impact 18.4 33.6 35.9 strength at 23°C. (kJ/m²) Loss in Charpy notched impact 18 15 15 strength (%)Properties after 500 hour exposure in sulfuric acid at 80° C. TensileModulus (MPa) 2341 2356 2354 Tensile Break Stress (MPa) 49.61 48.0448.86 Tensile Break Strain (%) 10.60 19.88 26.32 Charpy notched impact9.2 31.0 34.0 strength at 23° C. (kJ/m²) Loss in Charpy notched impact59 21 15 strength (%)

The results in the change in Charpy notched impact strength over timeduring exposure to the acid solution at an elevated temperature areillustrated in FIG. 22. As can be seen, the relative loss of strength ofsamples 6 and 10 is much less than the comparison sample.

EXAMPLE 3

Materials as described in Example 1 were melt mixed using a Coperionco-rotating, fully-intermeshing, twin-screw extruder with an overall L/Dof 40 and ten temperature control zones including one at the die. A highshear screw design was used to compound the additives into a resinmatrix. The polyarylene sulfide, impact modifier and lubricant were fedto the feed throat in the first barrel by means of a gravimetric feeder.The crosslinking agent was fed using a gravimetric feeder at the mainfeed throat and at barrel 6. Materials were further mixed then extrudedthrough a strand die. The strands were water-quenched in a bath tosolidify and granulated in a pelletizer.

Compositions of the samples are provided in Table 8, below. Amounts areprovided as weight percentages based upon the weight of the sample.

TABLE 8 Addition Sample Sample Sample Sample Component Point 11 12 13 14Lubricant main 0.3 0.3 0.3 0.3 feed Crosslinking main — 0.5 1.0 — Agentfeed Crosslinking barrel 6 — — — 1.0 Agent Impact main 15.0 15.0 15.015.0 Modifier feed Polyarylene main 84.7 84.2 83.7 83.7 Sulfide feedTotal 100.0 100.0 100.0 100.0

Following formation, tensile bars formed of the samples were tested fora variety of physical characteristics. Results are provided in Table 9,below.

TABLE 9 Sample Sample Sample Sample 11 12 13 14 Melt Viscosity (poise)2649 2479 2258 3778 Tensile Modulus (MPa) 2387 2139 2150 1611 TensileBreak Stress 46.33 49.28 51.81 42.44 (MPa) Tensile Break Strain 24.6222.60 14.45 53.62 (%) Std. Dev. 9.19 1.51 2.23 1.90 Notched Charpy 27.508.50 6.00 39.30 Impact Strength at 23° C. (kJ/m²) Std. Dev. 2.7 1.100.60 2.10

As can be seen, upstream feed of the crosslinking agent decreased theimpact properties of the composition, while downstream feed increasedthe tensile elongation by 118% and room temperature impact strength by43%.

EXAMPLE 4

Materials as described in Example 1 were melt mixed using a Coperionco-rotating, fully-intermeshing, twin-screw extruder with an overall L/Dof 40 and ten temperature control zones including one at the die. A highshear screw design was used to compound the additives into a resinmatrix. The polyarylene sulfide, impact modifier and lubricant were fedto the feed throat in the first barrel by means of a gravimetric feeder.The crosslinking agent was fed using a gravimetric feeder at barrel 6.Materials were further mixed then extruded through a strand die. Thestrands were water-quenched in a bath to solidify and granulated in apelletizer.

Compositions of the samples are provided in Table 10, below. Amounts areprovided as weight percentages based upon the weight of the sample.

TABLE 10 Addition Sample Sample Sample Sample Component Point 15 16 1718 Lubricant main 0.3 0.3 0.3 0.3 feed Crosslinking barrel 6 1.0 1.7 1.01.7 Agent Impact main 25.0 25.0 15.0 15.0 Modifier feed Polyarylene main73.7 73.0 83.7 83.0 Sulfide feed Total 100.0 100.0 100.0 100.0

Following formation, tensile bars formed of the samples were tested fora variety of physical characteristics. Results are provided in Table 11,below.

TABLE 11 Sample Sample Sample Sample 15 16 17 18 Melt Viscosity (poise)4255 4198 2522 2733 Density (g/cm³) 1.2 — — — Tensile Modulus (MPa)1582.00 1572.00 2183.00 2189.00 Tensile Break Stress 45.59 46.29 48.9849.26 (MPa) Tensile Break Strain 125.92 116.40 66.13 48.24 (%) Std. Dev.19.79 9.97 15.36 7.80 Elongation at Yield (%) 23 — — — Yield Stress(MPa) 42 — — — Flex Modulus (MPa) 1946.00 1935.00 2389.00 2408.00Flexural Stress @3.5% 48.30 48.54 68.55 68.12 (MPa) Notched Charpy 55.6051.80 43.60 19.10 Impact Strength at 23° C. (kJ/m²) Std. Dev. 1.00 1.401.50 1.50 Notched Charpy 13 — — — Impact Strength at −30° C. (kJ/m²)Notched Charpy 13.30 12.10 11.26 8.70 Impact Strength at −40° C. (kJ/m²)Std. Dev. 1.50 0.90 0.26 0.50 DTUL (1.8 MPa) (° C.) 97.20 97.60 101.70100.90 Water absorption (%) 0.07 — — —

EXAMPLE 5

Materials as described in Example 1 were utilized except for thepolyarylene sulfide, which was Fortron® 0320 linear polyphenylenesulfide available from Ticona Engineering Polymers of Florence, Ky.Materials were melt mixed using a Coperion co-rotating,fully-intermeshing, twin-screw extruder with an overall L/D of 40 andten temperature control zones including one at the die. A high shearscrew design was used to compound the additives into a resin matrix. Thepolyarylene sulfide and impact modifier were fed to the feed throat inthe first barrel by means of a gravimetric feeder. The crosslinkingagent was fed using a gravimetric feeder at barrel 6. Materials werefurther mixed then extruded through a strand die. The strands werewater-quenched in a bath to solidify and granulated in a pelletizer.

Compositions of the samples are provided in Table 12, below. Amounts areprovided as weight percentages based upon the weight of the sample.

TABLE 12 Addition Sample Sample Sample Sample Sample Component Point 1920 21 22 23 Crosslinking barrel 6 — — — 0.1 0.2 Agent Impact main — 1.53.0 1.5 3.0 Modifier feed Polyarylene main 100.0 98.5 97.0 98.4 96.8Sulfide feed Total 100.0 100.0 100.0 100.0 100.0

Following formation, tensile bars formed of the samples were tested fora variety of physical characteristics. Results are provided in Table 13,below.

TABLE 13 Sample Sample Sample Sample Sample 19 20 21 22 23 MeltViscosity (poise) 2435 2684 2942 2287 1986 Tensile Modulus (MPa) 32083207 3104 3245 3179 Tensile Break Stress 67.20 72.94 59.06 63.95 60.80(MPa) Tensile Break Strain 2.46 4.54 11.96 6.31 11.40 (%) Std. Dev. 0.321.11 1.24 2.25 3.53 Flex Modulus (MPa) 3103.00 3173.00 3031.00 3284.003156.00 Flexural Stress @3.5% 105.76 104.74 100.21 109.09 104.81 (MPa)Notched Izod Impact 2.90 5.20 5.60 4.10 4.30 Strength at 23° C. (kJ/m²)Std. Dev. 0.40 0.40 0.40 0.20 0.20 DTUL (1.8 MPa) (° C.) 105.60 104.00103.70 104.20 104.80

EXAMPLE 6

Materials utilized to form the compositions included the following:

Polyarylene sulfide: Fortron® 0214 linear polyphenylene sulfideavailable from Ticona Engineering Polymers of Florence, Ky.

Impact Modifier: LOTADER® 4720—a random terpolymer of ethylene, ethylacrylate and maleic anhydride available from Arkema, Inc.

Crosslinking Agent: Hydroquinone

Lubricant: Glycolube® P available from Lonza Group Ltd.

Materials were melt mixed using a Coperion co-rotating,fully-intermeshing, twin-screw extruder with an overall L/D of 40 andten temperature control zones including one at the die. A high shearscrew design was used to compound the additives into a resin matrix. Thepolyarylene sulfide, impact modifier and lubricant were fed to the mainfeed throat in the first barrel by means of a gravimetric feeder. Uponmelting and mixing of the above ingredients, the crosslinking agent wasfed using a gravimetric feeder at the main feed for samples 24 and 25and at barrel 6 for samples 26 and 27. Materials were further mixed thenextruded through a strand die. The strands were water-quenched in a bathto solidify and granulated in a pelletizer.

Compositions of the samples are provided in Table 14, below. Amounts areprovided as weight percentages based upon the weight of the sample.

TABLE 14 Addition Sample Sample Sample Sample Sample Component Point 2425 26 27 28 Lubricant main feed 0.3 0.3 0.3 0.3 0.3 Crosslinking barrel6 — — — 0.1 0.2 Agent Crosslinking main feed — 0.1 0.2 — — Agent Impactmain feed 15.0 15.0 15.0 15.0 15.0 Modifier Polyarylene main feed 84.784.6 84.5 84.6 84.5 Sulfide Total 100.0 100.0 100.0 100.0 100.0

Following formation, samples were tested for a variety of physicalcharacteristics. Results are provided in Table 15, below.

TABLE 15 Sample Sample Sample Sample Sample 24 25 26 27 28 MeltViscosity 2435 2797 3251 2847 2918 (poise) Tensile Modulus 2222 21642163 2184 2145 (MPa) Tensile Break 52.03 45.17 46.53 45.47 46.39 Stress(MPa) Tensile Break 36.65 50.91 63.39 38.93 41.64 Strain (%) Std. Dev.9.09 14.9 11.88 7.62 10.42 Elongation at Yield 5.75 5.49 5.76 5.53 5.70(%) Yield Stress (MPa) 52.03 50.21 50.77 51.39 50.85 Flexural Modulus2358.00 2287.00 2286.00 2305.00 2281.00 (MPa) Flexural Stress 70.5168.25 68.03 69.23 68.23 @3.5% (MPa) Notched Charpy 29.80 44.60 50.6042.30 45.90 Impact Strength at 23° C. (kJ/m²) Std. Dev. 4.10 2.40 1.901.90 1.60 Notched Charpy 5.90 9.30 11.00 9.60 9.80 Impact Strength at−40° C. (kJ/m²) Std. Dev. 1.00 0.90 1.20 0.80 1.30 DTUL (1.8 MPa) 99.1093.90 98.20 100.10 99.00 (° C.)

EXAMPLE 7

Materials utilized to form the compositions included the following:

Polyarylene sulfide:

PPS1—Fortron® 0203 linear polyphenylene sulfide available from TiconaEngineering Polymers of Florence, Ky.

PPS2—Fortron®0205 linear polyphenylene sulfide available from TiconaEngineering Polymers of Florence, Ky.

PPS3—Fortron®0320 linear polyphenylene sulfide available from TiconaEngineering Polymers of Florence, Ky.

Impact Modifier: LOTADER® AX8840—a random copolymer of ethylene andglycidyl methacrylate available from Arkema, Inc.

Crosslinking Agent: Terephthalic Acid

Lubricant: Glycolube® P available from Lonza Group Ltd.

Materials were melt mixed using a Coperion co-rotating,fully-intermeshing, twin-screw extruder with an overall L/D of 40 andten temperature control zones including one at the die. A high shearscrew design was used to compound the additives into a resin matrix. Thepolyarylene sulfide, impact modifier and lubricant were fed to the mainfeed throat in the first barrel by means of a gravimetric feeder. Uponmelting and mixing of the above ingredients, the crosslinking agent wasfed using a gravimetric feeder at barrel 6. Materials were further mixedthen extruded through a strand die. The strands were water-quenched in abath to solidify and granulated in a pelletizer.

Compositions of the samples are provided in Table 16, below. Amounts areprovided as weight percentages based upon the weight of the sample.

TABLE 16 Addition Sample Sample Sample Sample Sample Sample ComponentPoint 29 30 31 32 33 34 Lubricant main 0.3 0.3 0.3 0.3 0.3 0.3 feedCrosslinking barrel 6 1.0 1.0 1.0 Agent Impact main 15.0 15.0 15.0 15.015.0 15.0 Modifier feed PPS1 main 84.7 83.7 feed PPS2 main 84.7 83.7feed PPS3 main 84.7 83.7 feed Total 100.0 100.0 100.0 100.0 100.0 100.0

Following formation, samples were tested for a variety of physicalcharacteristics. Results are provided in Table 17, below.

TABLE 17 Sample Sample Sample Sample Sample Sample 29 30 31 32 33 34Tensile 2292 2374 2250 2427 2130 2285 Modulus (MPa) Tensile Break 50.9250.18 49.18 53.22 48.01 48.08 Stress (MPa) Tensile Break 5.79 2.84 23.7934.73 23.55 45.42 Strain (%) Std. Dev. 0.99 0.18 11.96 4.01 18.57 18.94Flexural 2279.00 2382.00 2257.00 2328.00 2292.00 2294.00 Modulus (MPa)Flexural Stress 71.11 74.94 69.72 72.39 67.95 68.95 @3.5% (MPa) Notched5.70 3.70 9.10 12.80 19.40 45.40 Charpy Impact Strength at 23° C.(kJ/m²) Std. Dev. 0.90 0.70 0.80 1.00 2.70 7.70 Notched 3.00 2.50 5.105.00 5.10 8.00 Charpy Impact Strength at −40° C. (kJ/m²) Std. Dev. 0.700.30 0.60 0.30 0.40 1.00 DTUL 101.00 105.50 100.00 102.90 99.90 100.40(1.8 MPa) (° C.)

EXAMPLE 8

Materials utilized to form the compositions included the following:

Polyarylene sulfide: Fortron® 0214 linear polyphenylene sulfideavailable from Ticona Engineering Polymers of Florence, Ky.

Impact Modifier: LOTADER® AX8840—a random copolymer of ethylene andglycidyl methacrylate available from Arkema, Inc.

Crosslinking Agent: Terephthalic Acid

Lubricant: Glycolube® P available from Lonza Group Ltd.

Materials were melt mixed using a Coperion co-rotating,fully-intermeshing, twin-screw extruder with an overall L/D of 40 andten temperature control zones including one at the die. A high shearscrew design was used to compound the additives into a resin matrix. Thepolyarylene sulfide, impact modifier and lubricant were fed to the mainfeed throat in the first barrel by means of a gravimetric feeder. Uponmelting and mixing of the above ingredients, the crosslinking agent wasfed using a gravimetric feeder at barrel 6. Materials were further mixedthen extruded through a strand die. The strands were water-quenched in abath to solidify and granulated in a pelletizer.

Compositions of the samples are provided in Table 18, below. Amounts areprovided as weight percentages based upon the weight of the sample.

TABLE 18 Addition Sample Sample Sample Sample Sample Sample ComponentPoint 35 36 37 38 39 40 Lubricant main 0.3 0.3 0.3 0.3 0.3 0.3 feedCrosslinking barrel 6 0.75 1.25 1.75 Agent Impact main 15.0 15.0 25.025.0 35.0 35.0 Modifier feed Polyarylene main 84.7 83.95 74.70 73.4564.70 62.95 Sulfide feed Total 100.0 100.0 100.0 100.0 100.0 100.0

Following formation, samples were tested for a variety of physicalcharacteristics. Results are provided in Table 19, below. Sample 39 wasnot injection moldable.

TABLE 19 Sample Sample Sample Sample Sample Sample 35 36 37 38 39 40Melt Viscosity 2323 2452 2955 3821 2025 5462 (poise) Tensile 2281 22982051 1721 — 1045 Modulus (MPa) Tensile Break 47.09 49.09 47.29 46.18 —39.81 Stress (MPa) Tensile Break 28.92 36.42 97.33 110.36 — 96.76 Strain(%) Std. Dev. 6.35 3.13 53.94 8.40 — 1.77 Elongation 5.28 8.58 36.00108.19 — 95.77 at Yield (%) Yield Stress 52.42 53.92 46.50 46.76 — 40.43(MPa) Flexural 2388.00 2349.00 2210.00 1750.00 — 1209.00 Modulus (MPa)Flexural Stress 71.52 71.70 63.15 50.52 — 34.41 @3.5% (MPa) Notched35.15 38.40 57.00 52.70 — 52.10 Charpy Impact Strength at 23° C. (kJ/m²)Std. Dev. 6.22 1.50 1.40 3.40 — 2.10 Notched 8.20 10.70 8.70 18.10 —14.10 Charpy Impact Strength at −30° C. (kJ/m²) Std. Dev. 1.50 1.60 0.200.90 — 0.80 Notched 7.26 9.20 8.00 16.80 — 12.47 Charpy Impact Strengthat −40° C. (kJ/m²) Std. Dev. 1.54 2.30 0.60 0.40 — 0.92 DTUL 99.90103.60 98.10 99.30 — 92.70 (1.8 MPa) (° C.) Water — — — — — 0.1absorption (%)

EXAMPLE 9

Materials utilized to form the compositions included the following:

Polyarylene sulfide: Fortron® 0214 linear polyphenylene sulfideavailable from Ticona Engineering Polymers of Florence, Ky.

Impact Modifier: LOTADER® AX8840—a random copolymer of ethylene andglycidyl methacrylate available from Arkema, Inc.

Crosslinking Agent: Terephthalic Acid

Lubricant: Glycolube® P available from Lonza Group Ltd.

Materials were melt mixed using a Coperion co-rotating,fully-intermeshing, twin-screw extruder with an overall L/D of 40 andten temperature control zones including one at the die. A high shearscrew design was used to compound the additives into a resin matrix. Thepolyarylene sulfide, impact modifier and lubricant were fed to the mainfeed throat in the first barrel by means of a gravimetric feeder. Uponmelting and mixing of the above ingredients, the crosslinking agent wasfed using a gravimetric feeder at barrel 6. Materials were further mixedthen extruded through a strand die. The strands were water-quenched in abath to solidify and granulated in a pelletizer.

Compositions of the samples are provided in Table 20, below. Amounts areprovided as weight percentages based upon the weight of the sample.

TABLE 20 Addition Sample Sample Sample Sample Component Point 41 42 4344 Lubricant main 0.3 0.3 0.3 0.3 feed Crosslinking barrel 6 1.0 1.11.25 1.25 Agent Impact main 15 20 25 30 Modifier feed Polyarylene main83.7 78.6 73.45 68.45 Sulfide feed Total 100.0 100.0 100.0 100.0

Following formation, samples were tested for a variety of physicalcharacteristics. Results are provided in Table 21, below.

TABLE 21 Sample Sample Sample Sample 41 42 43 44 Specific Gravity 1.251.20 1.15 1.20 (g/cm³) Tensile Modulus 2200 1600 1200 1700 (MPa) (50mm/min) Tensile Break 50 42 40 46 Strength (MPa) (50 mm/min) Elongationat 40 100 90 75 Break (%) (50 mm/min) Yield Stress (MPa) 55 42 40 48 (50mm/min) Yield Strain (%) 9 25 90 15 (50 mm/min) Flexural Modulus 22001700 1300 1900 (MPa) Flexural Strength 68 50 40 56 @3.5% (MPa) NotchedCharpy 40 55 50 50 Impact Strength at 23° C. (kJ/m²) Notched Charpy 1024 20 20 Impact Strength at −30° C. Unnotched Charpy Not Not Not NotImpact Strength at broken broken broken broken 23° C. DTUL (1.8 MPa) 102100 95 100 (° C.) Water absorption 0.05 0.07 0.1 0.05 (%) Vicatsoftening 270 270 270 270 temp. (A10N, ° C.) Vicat softening 200 160 110180 temp. (B50N, ° C.) Complex viscosity 79.994 289.27 455.19 — (0.1rad/sec, 310° C.) (kPa/sec) Hydrocarbon 14 23 — 19 volume uptake (%)

Samples 41, 42, and 43 were tested to determine complex viscosity aswell as melt strength and melt elongation as a function of Henckystrain. As a comparative material, Sample 3 as described in Example 2was utilized. Samples 41, 42 and 43 were done at 310° C. and sample 3was done at 290° C. Results are shown in FIG. 23, FIG. 24, and FIG. 25.

EXAMPLE 10

Samples 41, 42, and 43 described in Example 9 were tested to determinepermeation of various fuels including CE10 (10 wt. % ethanol, 45 wt. %toluene, 45 wt. % iso-octane), CM15A (15 wt. % methanol and 85 wt. %oxygenated fuel), and methanol. Sample No. 4 described in Example 2 wasutilized as a comparison material. Two samples of each material weretested.

Table 22, below provides the average sample thickness and effective areafor the samples tested with each fuel.

TABLE 22 Average Sample Sample Thickness (mm) Effective area (m²) CE10Aluminum blank - 1 1.50 0.00418 Aluminum blank - 2 1.50 0.00418 SampleNo. 4-1 1.47 0.00418 Sample No. 4-2 1.45 0.00418 Sample No. 41-1 1.470.00418 Sample No. 41-2 1.49 0.00418 Sample No. 42-1 1.47 0.00418 SampleNo. 42-2 1.46 0.00418 Sample No. 43-1 1.45 0.00418 Sample No. 43-2 1.470.00418 CM15A Aluminum blank-1 1.50 0.00418 Aluminum blank-2 1.500.00418 Sample No. 4-1 1.48 0.00418 Sample No. 4-2 1.49 0.00418 SampleNo. 41-1 1.49 0.00418 Sample No. 41-2 1.50 0.00418 Sample No. 42-1 1.470.00418 Sample No. 42-2 1.48 0.00418 Sample No. 43-1 1.46 0.00418 SampleNo. 43-2 1.47 0.00418 Methanol Aluminum blank - 1 1.50 0.00418 Aluminumblank - 2 1.50 0.00418 Sample No. 4-1 1.49 0.00418 Sample No. 4-2 1.490.00418 Sample No. 41-1 1.49 0.00418 Sample No. 41-2 1.51 0.00418 SampleNo. 42-1 1.48 0.00418 Sample No. 42-2 1.47 0.00418 Sample No. 43-1 1.470.00418 Sample No. 43-2 1.48 0.00418

The daily weight losses for each material and each fuel are shown inFIGS. 26-28. Specifically, FIG. 26 shows the daily weight loss for thesamples during the permeation test of CE10, FIG. 27 shows the dailyweight loss for the samples during the permeation test of CM15A, andFIG. 28 shows the daily weight loss for the samples during thepermeation test of methanol.

The average permeation rates for each sample with each fuel are providedin Table 23. Note that Sample No. 43 takes a longer time to arrive atequilibrium, so the linear regression fitting was generated based ondata between days 42 and 65 for this material, while the linear regressfitting was generated for the other materials between days 32 and 65.For methanol, the linear regression fitting was generated based on databetween days 20 and 65, but with Sample No. 604, the methanol linearregression fitting was generated based on data between days 30 and 65.Some samples show negative permeability, which is because the weightloss of the sample was lower than that of the aluminum blank.

TABLE 23 Average Normalized Normalized Per- Average permeationpermeation meation - Permeation - (g-mm/ (g-mm/ 3 mm 3 mm Sample day-m²)day-m²) thickness thickness CE10 Sample No. 4-1 0.06 0.05 ± 0.01 0.020.02 ± 0 Sample No. 4-2 0.05 0.02 Sample No. 41-1 0.07 0.04 ± 0.04 0.020.01 ± 0.01 Sample No. 41-2 0.01 0.00 Sample No. 42-1 0.06 0.06 ± 0 0.020.02 ± 0 Sample No. 42-2 0.06 0.02 Sample No. 43-1 2020 2.51 ± 0.43 0.730.84 ± 0.14 Sample No. 43-2 2.81 0.94 CM15A Sample No. 4-1 0.49 0.18 ±0.44 0.16 0.06 ± 0.15 Sample No. 4-2 −0.13 −0.04 Sample No. 41-1 0.500.11 ± 0.55 0.17 0.04 ± 0.18 Sample No. 41-2 −0.27 −0.09 Sample No. 42-1−0.13 0.27 ± 0.58 −0.04 0.09 ± 0.19 Sample No. 42-2 0.68 0.23 Sample No.43-1 2.04 2.29 ± 0.35 0.68 0.76 ± 0.12 Sample No. 43-2 2.53 0.84Methanol Sample No. 4-1 0.37 0.25 ± 0.18 0.12 0.08 ± 0.06 Sample No. 4-20.13 0.04 Sample No. 41-1 0.02 0.05 ± 0.05 0.01 0.02 ± 0.02 Sample No.41-2 0.08 0.03 Sample No. 42-1 0.28 0.25 ± 0.05 0.09 0.08 ± 0.02 SampleNo. 42-2 0.21 0.07 Sample No. 43-1 0.27 0.41 ± 0.2 0.09 0.14 ± 0.07Sample No. 43-2 0.55 0.18 The error was derived from the standarddeviation of duplicates in each sample.

These and other modifications and variations of the present inventionmay be practiced by those of ordinary skill in the art, withoutdeparting from the spirit and scope of the present invention. Inaddition, it should be understood that aspects of the variousembodiments may be interchanged both in whole or in part. Furthermore,those of ordinary skill in the art will appreciate that the foregoingdescription is by way of example only, and is not intended to limit theinvention so further described in such appended claims.

What is claimed is:
 1. A pipe section, comprising: a hollow body, thehollow body having an inner surface and an outer surface, the innersurface defining an interior; a barrier layer surrounding the hollowbody, the barrier layer having an inner surface and an outer surface,the barrier layer formed from a tape comprising a polyarylene sulfidecomposition, the polyarylene sulfide composition comprising apolyarylene sulfide and a crosslinked epoxy-functionalized impactmodifier.
 2. The pipe section of claim 1, wherein the polyarylenesulfide is polyphenylene sulfide.
 3. The pipe section of claim 1,wherein the polyarylene sulfide is a functionalized polyarylene sulfide.4. The pipe section of claim 1, wherein the polyarylene sulfidecomposition has an elongation at yield of greater than about 7%.
 5. Thepipe section of claim 1, wherein the polyarylene sulfide composition hasa tensile modulus of less than about 2300 MPa.
 6. The pipe section ofclaim 1, wherein the polyarylene sulfide composition has a notchedCharpy impact strength of greater than about 3 kJ/m² as measuredaccording to ISO Test No. 179-1 at a temperature of 23° C.
 7. The pipesection of claim 1, wherein the polyarylene sulfide composition has anotched Charpy impact strength of greater than about 8 kJ/m² as measuredaccording to ISO Test No. 179-1 at a temperature of −30° C.
 8. The pipesection of claim 1, wherein the crosslinked impact modifier comprisesthe reaction product of an epoxy functionality of the impact modifierand a crosslinking agent.
 9. The pipe section of claim 1, wherein thecrosslinked impact modifier comprises the reaction product of maleicanhydride functionality of the impact modifier and a crosslinking agent.10. The pipe section of claim 1, wherein the polyarylene sulfidecomposition is free of plasticizers.
 11. The pipe section of claim 1,wherein the tape is wrapped helically around the hollow body withrespect to a longitudinal axis of the hollow body.
 12. The pipe sectionof claim 1, wherein the polyarylene sulfide composition comprisesfibers.
 13. The pipe section of claim 12, wherein the fibers arecontinuous fibers.
 14. The pipe section of claim 13, wherein thecontinuous fibers are unidirectional.
 15. The pipe section of claim 1,wherein the barrier layer is bonded to the hollow body.
 16. The pipesection of claim 1, wherein the barrier layer and hollow body areunbonded,
 17. The pipe section of claim 1, wherein the hollow body isformed from a thermoplastic material.
 18. The pipe section of claim 17,wherein the thermoplastic material is a polyarylene sulfide composition.19. The pipe section of claim 18, wherein the polyarylene sulfidecomposition of the thermoplastic material includes a polyarylene sulfideand a crosslinked impact modifier.
 20. The pipe section of claim 1,wherein the hollow body is formed from a metal material.
 21. The pipesection of claim 1, wherein the epoxy-functionalized impact modifierincludes methacrylic monomer units.
 22. The pipe section of claim 21,the epoxy-functionalized impact modifier further includes α-olefinmonomer units.
 23. The pipe section of claim 1, wherein the crosslinkedimpact modifier is a reaction product of epoxy-functionalized monomerunits and a polyfunctional crosslinking agent.
 24. The pipe section ofclaim 23, wherein the polyfunctional crosslinking agent includes acarboxylic acid.
 25. The pipe section of claim 24, wherein thecarboxylic acid includes isophthalic acid, terephthalic acid, phthalicacid, or a combination thereof.
 26. The pipe section of claim 23,wherein the epoxy-functionalized monomer units includeepoxy-functionalized methacrylic monomer units.
 27. The pipe section ofclaim 23, wherein the polyarylene sulfide, impact modifier, andcrosslinking agent are melt-processed together.
 28. The pipe section ofclaim 1, wherein polyarylene sulfides constitute from about 20 wt. % toabout 90 wt. % by weight of the composition.
 29. The pipe section ofclaim 1, wherein the polyarylene sulfide is functionalized.
 30. The pipesection of claim 29, wherein the functionalized polyarylene sulfide is areaction product of a polyarylene sulfide and a disulfide compoundhaving a reactive functionality.
 31. A pipe section, comprising: ahollow body, the hollow body having an inner surface and an outersurface, the inner surface defining an interior; a barrier layersurrounding the hollow body, the barrier layer having an inner surfaceand an outer surface, the barrier layer comprising a continuous fiberreinforced polyarylene sulfide composition, the polyarylene sulfidecomposition comprising a polyarylene sulfide and a crosslinkedepoxy-functionalized impact modifier.
 32. The pipe section of claim 31,wherein the barrier layer is formed from a tape.
 33. The pipe section ofclaim 31, wherein the continuous fibers are unidirectional.